|Series||Sonic the Hedgehog|
December 23, 1998
Sonic Adventure[a] is a 1998 platform game for Sega's Dreamcast and the first main Sonic the Hedgehog game to feature 3D gameplay. The story follows Sonic the Hedgehog, Miles "Tails" Prower, Knuckles the Echidna, Amy Rose, Big the Cat, and E-102 Gamma in their quests to collect the seven Chaos Emeralds and stop series antagonist Doctor Robotnik from unleashing Chaos, an ancient evil. Controlling one of the six characters—each with their own special abilities—players explore a series of themed levels to progress through the story. Sonic Adventure retains many elements from prior Sonic games, such as power-ups and the ring-based health system. Outside the main game, players can play minigames like racing and interact with Chao, a virtual pet.
Sonic Team began developing Sonic Adventure in 1997, after the cancellation of the Sega Saturn game Sonic X-treme. Led by director Takashi Iizuka and producer Yuji Naka, the team strove to reinvent Sonic for the 3D era of video games. Adventure features a stronger emphasis on storytelling and role-playing elements in contrast to previous Sonic games, while Yuji Uekawa redesigned the series' characters for their transition to 3D. Sonic Team attempted to demonstrate the technical prowess of the Dreamcast with realistic graphics and drew inspiration from locations in Peru and Guatemala. The soundtrack was primarily composed by Jun Senoue, who preferred rock music over the electropop of previous Sonic games.
Following its unveil at the Tokyo International Forum in August 1998, Sonic Adventure was highly anticipated, and it was released in Japan in December 1998 and worldwide in September 1999. It received critical acclaim and became the Dreamcast's bestseller, with 2.5 million copies sold by August 2006. Reviewers considered Adventure a major technical advancement and praised the visuals and gameplay. Though critics noted glitches and camera problems, and reactions to the audio were mixed, Sonic Adventure received positive reviews; some speculated that it could help re-establish Sega as the dominant console manufacturer after the unsuccessful Saturn.
Journalists have retrospectively ranked Sonic Adventure among the best Sonic games, and it is recognized as an important release in both the series and the platform genre. Many characters and concepts introduced in Adventure recur in later Sonic games. A sequel, Sonic Adventure 2, was released in 2001. Adventure was ported to the GameCube and Windows with altered graphics and more challenges in 2003, while a high-definition version was released for the PlayStation 3 and Xbox 360 in 2010 and for Windows in 2011. Reviews for these releases were less positive; critics felt the game had not aged well and ran at an inconsistent frame rate.
Sonic Adventure is a 3D platform game with action and role-playing elements. Players control one of six anthropomorphic protagonists as they venture to defeat Doctor Robotnik and his robot army, who seek the seven magical Chaos Emeralds and the evil entity Chaos. Six player characters are unlocked as the game progresses, each with their own story and attributes. Sonic the Hedgehog performs a spin dash, homing attack, and light-speed dash; Miles "Tails" Prower flies, swims, and attacks robots using his tails; Knuckles the Echidna glides, climbs walls, and punches; Amy Rose can defeat enemies using her hammer; Big the Cat is slow and carries a fishing rod he can cast; and E-102 Gamma can shoot laser beams.
At the start of the game, the player is placed in one of several Adventure Fields, open-ended hub worlds inhabited by advice-giving non-player characters. The player character is guided and instructed by the voice of Tikal the Echidna. Through exploration, the player discovers entrances to levels called Action Stages, some of which must be opened using keys hidden in the Adventure Field.: 141–142 Once the player accesses an Action Stage, they are tasked with a specific objective, which is different for each character. Sonic must reach the level's end like in prior Sonic the Hedgehog games; Tails must reach the end before Sonic; Knuckles must find three hidden shards of the Master Emerald; Amy must solve puzzles and avoid being caught by a robot; Big must fish for his pet frog; and Gamma must fight his way through stages using projectiles as a defense.: 140
Some levels include minigames separate from the main story. These feature different styles of gameplay, among them rail shooting, racing, and sandboarding. Some minigames can only be accessed with particular characters. Fulfilling certain objectives allows the player to obtain bonus items. Unlocked minigames and stages the player has completed can be accessed from a Trial Mode on the title screen.
Like previous Sonic the Hedgehog games, players collect golden rings as a form of health: if the player character is in possession of rings when they are hit by an enemy or other hazard, they will survive, but their rings will scatter and blink before disappearing. Canisters containing power-ups such as speed shoes, additional rings, invincibility, and elemental shields are also hidden in levels. In several stages, the player engages Robotnik or Chaos in a boss fight and must deplete the boss's health meter to proceed. Each character starts with a limited number of lives, and the player loses a life if the character drowns, gets crushed, or is hit without any rings in their possession. The game ends when the player runs out of lives. Lives can be replenished by collecting 100 rings or a 1-up.
Players may also discover Chao Gardens, hidden, protective environments inhabited by Chao, a virtual pet. Players can hatch, name, and interact with a Chao, and raise the status of their Chao by giving it small animals found by defeating robots. The Dreamcast's handheld Visual Memory Unit (VMU) allows the player to download the minigame Chao Adventure, in which their Chao walks through a course to evolve and improve its skills. Evolving one's Chao improves its performance in competitions called Chao Races. Eggs that can produce special types of Chao are hidden throughout the Adventure Fields. Players can earn emblems by playing through Action Stages, searching through the Adventure Fields, or winning Chao Races. Each Action Stage has three emblems that can be earned by replaying the stages and fulfilling objectives, such as beating the level within a time limit.
Doctor Robotnik seeks a new way to defeat his longtime nemesis Sonic and conquer the world. During his research, he learns about an entity called Chaos—a creature that, thousands of years ago, helped to protect the Chao and the all-powerful Master Emerald, which balances the power of the seven Chaos Emeralds. When a tribe of echidnas sought to steal the power of the Emeralds, breaking the harmony they had with the Chao, Chaos retaliated by using the Emeralds' power to transform into a monstrous beast, Perfect Chaos, and wipe them out. Tikal, a young echidna who befriended Chaos, imprisoned it in the Master Emerald along with herself. Robotnik shatters the Master Emerald to release Chaos and tests the creature's natural form on the city of Station Square.
When Sonic sees local police fail to defeat Chaos, he and Tails work to stop Robotnik from empowering it with the Chaos Emeralds. Knuckles, the only remaining echidna, sets out to find the shards of the Master Emerald and repair it. Robotnik activates a new series of robots, including one named Gamma, and orders them to find Froggy, an amphibian who ate a Chaos Emerald. Froggy's owner, Big, seeks to find him as well. In Station Square, Sonic's friend Amy finds a Flicky being pursued for a Chaos Emerald in its possession, and decides to protect it. When both are captured, Amy convinces Gamma not to work for Robotnik; Gamma helps her to escape before seeking out and destroying the other robots in his series, sacrificing himself in the process.
Although Sonic disrupts Robotnik's plans, Chaos manages to absorb all the Chaos Emeralds and transforms into Perfect Chaos; it rebels against Robotnik and destroys Station Square. Through flashbacks from Tikal (who was also released from the Master Emerald), Sonic realizes that Chaos has been in constant torment and sorrow, and that imprisoning it again will not stop it. He uses the Chaos Emeralds to transform into Super Sonic and defeats Perfect Chaos. Chaos calms down when it sees the Chao living peacefully in Station Square, and Tikal takes it somewhere safe to live in peace. Afterward, Sonic pursues a fleeing Robotnik.
During the early 1990s, Sega was one of the most successful video game companies due to the rise of its Genesis console. Genesis sales were driven by the popularity of Sega's flagship franchise of 2D platform games, Sonic the Hedgehog. During this time, series co-creator Yuji Naka worked with Sega Technical Institute (STI) in the United States to develop Sonic games. After the completion of Sonic & Knuckles in 1994, Naka returned to Japan to work with Sonic Team. STI began developing Sonic X-treme for the Sega Saturn, planned as the first Sonic the Hedgehog game to feature full 3D gameplay. X-treme suffered a series of setbacks and was canceled in 1997. The cancellation is an important factor in the Saturn's commercial failure, leaving it with no original Sonic platform game. Meanwhile, Naka and Sonic Team developed original Saturn games, such as Nights into Dreams.: 67 
Naka still wanted to make a 3D Sonic game, and felt that only Sonic Team should do it; for this reason, he refused to let STI use the Nights game engine for X-treme, a factor in that game's cancellation. Due to the lack of Sonic games on the Saturn,[b] according to Retro Gamer, Sonic became part of the "background" by mid-1997, so "it was astonishing to see that, just six years after his debut, Sonic was already retro." In August 1996, Nights into Dreams designer Takashi Iizuka proposed a role-playing-style Sonic game with a greater emphasis on storytelling, which formed the basis of Sonic Adventure. Iizuka felt that Sonic fans had been let down because the team was not focusing on the series. Additionally, Kazuyuki Hoshino, who would serve as art director on Sonic Adventure, said he thought during the Saturn era Sonic had become outdated and strove to reinvent the character.
Sonic Team started to work on Sonic Adventure in April 1997 on the Saturn with a 20-strong team.: 139  Sonic Team created the first prototype using the Nights engine, but the Saturn's limited capabilities made development difficult.: 65 Sega president Hayao Nakayama informed Naka of the Saturn's successor, the Dreamcast, and he believed the new console would allow Sonic Team to create the ultimate Sonic game.: 67 When the team learned the Dreamcast was nearing completion, they moved development to take advantage of its greater quantity of RAM, stronger CPU, and the VMU. Not wanting to waste their completed work, they placed it as a bonus in the compilation game Sonic Jam, the final Sonic game for the Saturn.: 65 
Iizuka served as director on Sonic Adventure, while Naka produced. One of the largest video games created at the time, the team had grown to 60 after 10 months. Sonic Team undertook development in conjunction with the Dreamcast, aiming to release the game in December 1998, even if it meant making improvements after release.: 69  Developing Sonic Adventure at the same time as the system, which was not completed until two months before the game's release, gave Iizuka influence over the console's development; for example, he was able to request more RAM for the console specifically for Sonic Adventure.
Characters and art
Sonic Team felt challenged by the new hardware to recreate Sonic and his world in a new way. They began development using the character designs from the Genesis games, but quickly discovered the characters' bodies were too short and their heads too big, making them difficult to see. Retro game characters, such as Pac-Man, were also being reborn in a more "urban" fashion around the same time, something that made Sonic Team jealous and feel the original character designs were dated. As such, Yuji Uekawa redesigned each character to suit the transition to 3D and to give them "new, edgy, more Western" design. Looking to the animation of Walt Disney and Looney Tunes for inspiration, he made Sonic more mature, taller and slimmer, and gave him longer quills. He darkened his blue color and gave him green irises in reference to Green Hill Zone. Uekawa tried to make Sonic look like a comic book character and compared the style to graffiti. After redesigning Sonic, he made the other characters fit this new art style. Hoshino noted that the characters' longer limbs made it easier to recreate their 2D poses in 3D.
Sonic Adventure features two new playable characters, Big and Gamma. Sonic Team had already implemented an in-game fishing rod with no context or use, leading to the creation of Big. Big was designed to be giant and relaxed so the player would not expect something more intense. Gamma and his playstyle were created in response to fans who wanted elements of a shoot 'em up in Sonic and because of Iizuka's desire to include "some type of satisfying gameplay that couldn't be done with Sonic". Neither Big nor Gamma were intended to play a large role, thus both of their campaigns were short. Iizuka also wanted to create a villain who would have been impossible to make on older hardware. He settled on something liquid and transparent and created Chaos. Iizuka presented the concept to Naka, who was impressed. Chaos was originally intended to have realistic blue scales in his final form, but this was abandoned because of the technological constraints of the Dreamcast.
While some Sonic games, such as 1993's Sonic CD, contained limited voice work, Sonic Adventure was the first Sonic game to feature extensive voice acting. The decision was made early in development as the game was more story-focused than previous Sonic games. Sonic Team's staff had differing opinions about how Sonic should sound. Iizuka recalled that the only element they agreed on was to avoid using an anime voice actor, favoring a film actor with an "over-the-top" voice. Sonic Team cast Jun'ichi Kanemaru as Sonic. In an interview celebrating his 30th anniversary as a voice actor, Kanemaru said one reason he was cast was because of his ability to speak English. After Sonic Team USA was formed, they hired American actors to translate the Japanese script. The English-language voice cast consists of Ryan Drummond as Sonic, Corey Bringas as Tails, Michael McGaharn as Knuckles, Jennifer Douillard as Amy, Jon St. John as Big and E-102 Gamma, and Deem Bristow as Robotnik. Iizuka used Sonic Adventure to introduce Robotnik's Japanese name, "Dr. Eggman", to western audiences; he accomplished this by having Sonic insult Robotnik when they meet for the first time in-game. Similarly, he avoided referring to Tails as "Miles", which he was commonly called in Japan.
Because Sonic Adventure was a Dreamcast launch game, the team strove to demonstrate the console's capabilities with realistic graphics. To achieve a more realistic feel for the environments, the core members of Sonic Team visited temples, jungles, and ancient ruins in Mesoamerican landscapes, including Cancún, Guatemala, and Peru. While Sonic Team members had to draw artwork by hand for games in the past, for Sonic Adventure they were able to use photographs taken during their visits as textures. The greatest influences were the Tikal ruin in Guatemala and Machu Picchu in Peru. The character Tikal was inspired by Peru and took her name from the Guatemalan ruins.: 68  The 3D visuals were created using a Voodoo2 graphics chip.
The levels were designed to feature gameplay similar to the original Genesis games and to take at least five minutes to complete. One of the biggest challenges the Adventure designers faced was transitioning Sonic's 2D style to 3D. In the Genesis Sonic games, the player simply had to go right to reach the end of a level, but in Sonic Adventure they could move in every direction. The designers created models for the stages before testing it as the player character, resulting in trial and error. This made Iizuka realize the importance of the game's camera. Some levels, such as the Lost World, were rebuilt dozens of times. Sonic Team split levels into parts to save memory. One particular difficulty was defeating enemies; in the 2D games, enemies were beaten simply by jumping on them, but this was harder to achieve in a 3D game. Therefore, Sonic was given the ability to target enemies in mid-air.
Iizuka said the cinematic sequences were conceived to take advantage of the environments, "giving the player an element of discovery in addition to the platforming". The team also wanted to add elements unexpected in a platform game; for example, the level in which Tails sandboards was inspired by a group of sandboarders in Ica, Peru.: 68  Some levels reference past Sega games, such as Ice Cap (1994's Sonic the Hedgehog 3) and the Tornado levels (1995's Panzer Dragoon).: 142 When seeing the completed level designs, Iizuka and Naka decided to re-purpose them for other player characters. Iizuka said they felt it would be "a waste if Sonic just quickly ran through the levels that we spent so much time creating". The first characters besides Sonic added to the game were Tails and Knuckles; Tails' stages turned portions of Sonic's levels into races, while Knuckles' treasure-hunting missions were designed as a contrast to the others' straightforward ones. Sonic Adventure was the first time Amy was playable in a Sonic platformer, and Iizuka aimed to use her to add tension, such as hiding from pursuers, that Sonic's gameplay could not offer.
Because Sonic Adventure had a stronger emphasis on storytelling than previous games in the series, the team implemented hub worlds to "draw the players deeper into the world." The hub worlds' emphasis on exploring to find new areas and power-ups was inspired by The Legend of Zelda. When seeing the completed level designs, Iizuka and Naka decided to re-purpose them for other player characters. According to Iizuka, the team tried to include as much content as possible. One addition was the Chao-raising system, which Iizuka conceived to take advantage of the VMU.: 70 Sonic Team had used a similar virtual pet system, the "A-Life", in Nights into Dreams; Iizuka used the A-Life as a base, while improving it with the VMU and the option to improve its skills.: 71 Iizuka hoped it would be made into a character players could touch and raise. It was also designed to appeal to casual gamers not familiar with games like Sonic, and to add replay value. The design took considerable time to finalize and had to be made as simple as possible because the virtual pet's look changes form as it evolves.
Sonic Adventure's score was primarily composed by Jun Senoue, with additional music by Fumie Kumatani, Kenichi Tokoi, and Masaru Setsumaru. Adventure was Senoue's first project as sound director and its scope meant he had many more responsibilities, including schedule management, compared to his previous games. Despite this, Senoue said he did not feel much pressure, as he was a Sonic fan and had contributed to previous games' soundtracks.
In contrast to previous Sonic games, which featured electropop soundtracks, the Adventure sound team preferred "hot, funky, and rock 'n' roll" music. Iizuka noted that Sonic Team's primary goal with Adventure was "to evoke the essence of Sonic by going from 2D to 3D", and felt the music needed to exceed fan expectations due to previous Sonic soundtracks' popularity. He stated a new style was adopted because the Dreamcast's sound was a significant advance from that of the Genesis; Senoue added he felt more comfortable composing rock music and wanted to create music everyone could enjoy. Despite the different styles, Senoue did retain some music from the Genesis Sonic games: the music for the Windy Valley and Twinkle Park levels were rearranged from Sonic 3D Blast (1996), while the level clear jingle was taken from Sonic 3. He chose to reuse his 3D Blast tracks because he felt they were strong enough to be more widely heard, as they were only used the Genesis version (which was not released in Japan).
Senoue composed several songs with English lyrics to highlight the various characters' personalities, and collaborated with Tokoi and Kumatani to polish them. The main theme, "Open Your Heart", was performed by Hardline's Johnny Gioeli; other songs were performed by Gioeli, Marlon Saunders, Dred Foxx, Ted Poley, Nikki Gregoroff, and Tony Harnell.: 143 Sonic Adventure marked Senoue's first collaboration with Gioeli; the two later formed the band Crush 40 (originally known as Sons of Angels), and continue to make music together. Iizuka was inspired to use "Open Your Heart" as the final boss music by films, which he noted often use main themes during dramatic events. Iizuka also felt that the songs helped define Knuckles and Amy's personalities, as they had not received much character development in Sonic games until Adventure.
A two-disc soundtrack, Sonic Adventure "Digi-LOG Conversation" Original Sound Track, was released in Japan in January 1999. In May 2011, the soundtrack was rereleased to commemorate the Sonic franchise's 20th anniversary. A two-volume digital soundtrack was also released on iTunes and Spotify in September 2014 and January 2017, respectively. Brave Wave Productions released a vinyl LP version of the soundtrack including interviews with Senoue and Iizuka in 2018.
Sonic Adventure was kept a secret during production, though screenshots were leaked in mid-1998 and plans for a 3D Sonic game had long been rumored. It was unveiled by Naka and the rest of Sonic Team on August 22, 1998, at the Tokyo International Forum. The team showed off several dynamic elements, such as a chase sequence from the first level and Tails' sandboarding sequence. Naka described the debut as intense, having "[given his] all" to make it fit for release.: 69
On December 23, 1998, Sonic Adventure was released in Japan. The Japanese version shipped with many glitches; according to Iizuka, this was because the game was produced on a tight schedule, so Sonic Team did not have time to fix them. Several members of Sonic Team flew to Sega of America to establish Sonic Team USA and patch and translate the game. Iizuka felt that the Dreamcast was going to launch in several months and the game needed to be localized.: 69 The localized version was released in North America on September 9, 1999 as a launch title, and in Europe on September 23, 1999. It includes Japanese and English-language audio tracks, as well as Japanese, English, Spanish, French and German subtitles. Online features—including Chao daycare and downloadable content (DLC) such as minigames and new level assets—were also added. The localized version was later released in Japan as Sonic Adventure International.: 69 
Prior to the launch of the Dreamcast in the United States, Sega made an exclusive deal with Hollywood Video to allow customers to rent the Dreamcast console along with a non-retail version of the game, Sonic Adventure: Limited Edition. The promotion began on July 15, 1999 and took place at 1,055 Hollywood Video stores across the country. Additionally, the American release of Studio Pierrot's Sonic the Hedgehog (1996) original video animation coincided with the Western release of Sonic Adventure, while DIC Entertainment's Sonic Underground (1999–2000) was commissioned to help promote the game.
Upon its North American launch, there were complaints of a number of Sonic Adventure discs refusing to load. Sega America explained that this was a software problem due to errors at one manufacturing facility and that they were able to track the faulty software, adding that most copies of the game were unaffected and that customers could trade defective copies for working ones at retailers.
As the first fully 3D Sonic platform game, Sonic Adventure was highly anticipated. It received critical acclaim,: 143  and Computer and Video Games (CVG) called it one of the greatest video games of all time. It is the bestselling Dreamcast game; by August 4, 2006, it had sold 2.5 million copies, including 440,000 in Japan and 1.27 million in the US.: 143 
The visuals and presentation attracted wide acclaim. Arcade magazine described it as a "quantum leap forward" in aesthetics and visual detail in video games, and Hyper estimated they even exceeded what was possible on high-end personal computers. IGN called it the most graphically impressive platform game released up to that date, praising its cinematic sequences and describing it as "engrossing, demanding, and utterly awe-inspiring". GameSpot agreed and said only Soulcalibur's graphical quality surpassed that of Sonic Adventure. Edge felt the graphical features showed off the Dreamcast's potential to the fullest and that the game was "perfect" as a showcase for the system.
The audio received mixed responses. GameSpot and Game Revolution called the full-motion video (FMV) cutscenes and voice acting well-produced and fitting, though GameSpot noted poor lip-synching. IGN thought the cutscenes were repetitive and voiced strong disapproval of the voice acting, declaring it "a complete joke" and "downright awful". IGN had a particular distaste for Tails' voice, and retrospectively called it among the most annoying to feature in a video game. AllGame was conflicted; they appreciated Tails' portrayal but found Sonic's and Knuckles' voices unfitting. GameSpot and AllGame praised the rock-style music, but Game Revolution described the score as "absolutely horrible".
The gameplay was generally praised. GameSpot admired the straightforward, linear approach to the 3D platform genre and particularly praised it for keeping the basic gameplay of the original Genesis games. IGN said the game would keep players busy even after completion, noting its internet connectivity and other extras. On the other hand, Game Revolution said apart from being quicker, it did not advance the platform genre's design. Retrospectively, 1001 Video Games You Must Play Before You Die called its environments vast and twisted, stating it "brilliantly" captured traditional Sonic elements. The Chao minigame was noted as a major departure from the gameplay of the series. GameSpot wrote that "while really just a diversion", the Chao were an interesting, fun addition, singling out their internet functions as a highlight. AllGame said the Chao helped increase the replay value, although it was "strange", required patience, and did not provide bonuses in the main game. Game Revolution called the Chao "a neat addition" and praised its use of the VMU.
Some critics compared Sonic Adventure to Super Mario 64—Nintendo's "groundbreaking" 1996 game that propelled the Nintendo 64 and the 3D platform genre. Edge said Sonic Adventure was a worthy rival to Super Mario 64, but AllGame wrote that Sonic Adventure was not as ambitious and that those looking for exploration would be disappointed with its linear gameplay. They compared it to the similarly linear Crash Bandicoot but felt Sonic Adventure was more confined. Still, they praised the gameplay as varied and said its replay value was strong. Game journalists Rusel DeMaria and Johnny L. Wilson retrospectively wrote Sonic Adventure was not as strong as Super Mario 64 and "failed to catch on with players in nearly the way that [Mario] had done", though it had fascinating features, such as "the use of the Tamagotchi-like memory card to incubate eggs for little pet creatures" and "some good action segments".
The camera system and glitches were criticized by many reviewers. IGN called the camera "incredibly" frustrating and inconsistent, and GameSpot noted it caused problems with collision detection. Edge complained the camera sometimes goes behind walls. Authors from GamesRadar retrospectively wrote that Sonic Adventure was "horrendously buggy", singling out falling through floors and getting stuck, but also said the sheer amount of content made up for this.
GameSpot thought Sonic Adventure redefined the possibilities of the platform genre, and according to CVG, "many things you thought were impossible to see and experience in computer games are now here". According to Next Generation, "Expert gamers may beat the game in only a day or two but, even then, the ride is worth the price of admission." AllGame wrote that the game was an impressive showing of the Dreamcast's potential and that it was among the best of the series. Edge said its criticisms such as scenery pop-up and instances of poor collision detection are "minor flaws in an otherwise very fine piece of work". Arcade and CVG speculated the game could save the Dreamcast, which had not sold well by the end of 1998. CVG also thought it could re-establish Sega as the dominant console manufacturer after the relatively unsuccessful Saturn.
Sonic Adventure won a Blockbuster Entertainment Award in the "Favorite Video Game" category, and it was a runner-up for GameSpot's annual "Best Console Platform Game" award, which went to Rayman 2: The Great Escape.
Sonic Adventure DX: Director's Cut
In 2001, Sega announced it would transition from a first-party to a third-party software publisher, in response to the international failures of the Saturn and Dreamcast. Wanting to reach new players by creating an enhanced version of one of its older games, in June 2003 Sega released Sonic Adventure DX: Director's Cut, a port of Sonic Adventure for the GameCube and Windows.: 141  While mostly identical to the original release, Sonic Adventure DX features updated graphics, including higher-resolution textures and more detailed character models, aims for a frame rate of 60 instead of 30, and sports a redesigned Chao-raising system that uses connectivity with the Game Boy Advance (GBA). It includes 60 new missions and the option to unlock all 12 Sonic games released for the Game Gear. Additionally, Metal Sonic can be unlocked as a playable character if all 130 emblems are collected. These features were added to appeal to players of the original game.: 141
Sonic Adventure DX received mixed reviews. GameSpot was disappointed the rerelease did not address the problems of the original version, irritated the graphics were only marginally different, and dissatisfied with its collision detection. GameSpot offered some praise for the extra features, such as the missions, but concluded players were better off playing the Dreamcast version. IGN agreed, calling it "a sloppy port of a game that has long been undeserving of its high praise." IGN noted its frequent frame rate drops and described its camera one of the worst in a video game. IGN said the connectivity to the GBA Sonic games added depth but concluded this was not enough to compensate for the port's problems. Nintendo World Report was more positive, praising the Game Gear games for retaining their multiplayer support and finding Sonic and Tails’ gameplay enjoyable.
In September 2010, Sega rereleased Sonic Adventure as a downloadable game for the Xbox 360 and PlayStation 3, followed by a Windows release in March 2011 via Steam. This version is based on Sonic Adventure DX and supports high-definition visuals at a 4:3 aspect ratio. Sonic Adventure DX's additional content was removed, but the mission mode and Metal Sonic can be reimplemented by purchasing additional DLC. The game was also included in the Dreamcast Collection compilation in 2011, and is backwards-compatible with the Xbox One and Xbox Series X/S.
Reviews of the 2010 rerelease were generally unfavorable, with criticism directed at the perceived lack of effort put into the port. IGN called it "so fundamentally flawed that it borders on unplayable", observing that the sections that worked best required the least input from the player. IGN criticized the lack of widescreen support but offered minor praise for its steady frame rate. 1UP.com lambasted the port for what they called its slapdash quality, criticizing its display, controls, and dated design, and saying it "feels like it wasn't even tuned for the Xbox 360 controller and its analog sticks". Destructoid was less harsh, writing that fans of the franchise would be able to enjoy the game but warned casual players that "all you'll find is a relic that was once considered greatness".
With most contemporary 3D platform games focusing on exploration and collecting items, Sonic Adventure stood out with its linear gameplay. According to GamesRadar, as one of the first sixth-generation console games, it changed the industry "forever". Joystiq wrote that both Adventure and the original Sonic the Hedgehog had innovated—in 3D and 2D games, respectively—through effective linear level design and by feeling "good to play". In 2009, GamePro listed Sonic Adventure as the seventh-best platform game of all time, saying it had not aged well in certain aspects but its core gameplay remained among the best of the Sonic series. Several journalists ranked the game among the series' best, but Kotaku argued the addition of voice acting and greater focus on plot changed Sonic into "a flat, lifeless husk of a character, who spits out slogans and generally has only one personality mode, the radical attitude dude, the sad recycled image of vague '90s cultural concept".
Many of Sonic Adventure's designs and concepts were reused in later Sonic games. The direction, basic gameplay, and Uekawa's modernized character designs became series staples. The first level in the 2006 Sonic the Hedgehog reboot heavily references Sonic Adventure's Emerald Coast stage. To celebrate the Sonic series' 20th anniversary in 2011, Sega released Sonic Generations, which reused aspects from past games in the franchise. The Xbox 360, PlayStation 3, and Windows versions contain reimagined versions of the Speed Highway level and the Perfect Chaos boss fight, and the Nintendo 3DS version contains a remake of Emerald Coast.
Several characters that first appeared in Sonic Adventure appeared in later games. As well as appearing in Sonic Generations, Chaos is an antagonist in the 2017 entry Sonic Forces; it and Gamma are playable characters in the 2004 fighting game Sonic Battle; and a recreation of its boss fight appears in Mario & Sonic at the Olympic Winter Games. The Chao creatures also feature predominantly in later games. One of the characters introduced in Adventure, Big the Cat, became infamous for his negative reception. Game Informer considered his gameplay painful and boring, while Destructoid decried his portrayal as a "mentally handicapped imbecile" and his voice actor's incoherent performance. Big is widely considered by video game journalists the worst character in the Sonic franchise, and was named one of the worst game characters in a poll conducted by 1UP.com.
On October 4, 1999, Sega announced that a sequel to Sonic Adventure was in development. Sonic Adventure 2 made its debut at E3 2000 and was released in June 2001. The sequel was designed to be more action-oriented than the slower-paced, story-centric Adventure and to give all the characters equal playtime. Like its predecessor, Sonic Adventure 2 received positive reviews. A concept for Sonic Adventure 3 was reworked into the 2008 game Sonic Unleashed. In 2017, Iizuka stated there were no plans for a third Sonic Adventure game, saying it would not advance the series' design. He did not rule out the idea, saying "If we can get the gameplay to evolve and get to a place where Adventure 3 makes sense, then you might see an Adventure 3 come out". In December 2018, Iizuka expressed interest in remaking Sonic Adventure.
The plot of Sonic Adventure was adapted in the second season of the 2003 Sonic the Hedgehog anime series Sonic X. American licensing corporation 4Kids Entertainment hired a new voice cast for the English-language dub but the Japanese cast from the games reprised their roles in the original version of the show. Archie Comics also adapted the game in its Sonic the Hedgehog comic book series. The comic offered an explanation for the altered character designs and established that Station Square was hidden beneath Sonic's planet, Mobius.
- "First Look at Sonic Adventure" (PDF). Computer and Video Games (203). October 1998. Archived (PDF) from the original on November 14, 2017. Retrieved November 11, 2017.
- Varanini, Giancarlo (June 23, 2003). "Sonic Adventure DX Director's Cut Review". GameSpot. CBS Interactive. Archived from the original on August 5, 2017. Retrieved November 12, 2017.
- Sonic Adventure instruction manual (PDF). Sega. 1999.
- Pétronille, Marc; Audureau, William (2014). The History of Sonic the Hedgehog. Pix'n Love. ISBN 978-1926778969.
- Ferris, Colin (September 1, 1999). "At least Chao don't piddle on the rug . . . Review". Game Revolution. CraveOnline. Archived from the original on September 4, 2017. Retrieved November 12, 2017.
- Justice, Brandon (September 8, 1999). "Sonic Adventure". IGN. Ziff Davis. Archived from the original on October 30, 2014. Retrieved November 12, 2017.
- Bartholow, Peter (December 31, 1998). "Sonic Adventure Review". GameSpot. CBS Interactive. Archived from the original on October 29, 2017. Retrieved November 12, 2017.
- Marriott, Scott. "Sonic Adventure – Review". AllGame. All Media Network. Archived from the original on November 14, 2014. Retrieved January 22, 2018.
- Casamassina, Matt (June 20, 2003). "Sonic Adventure DX Director's Cut Review". IGN. Ziff Davis. Archived from the original on August 5, 2017. Retrieved November 12, 2017.
- Thorpe, Nick (December 28, 2018). "The Making of: Sonic Adventure". Retro Gamer. PressReader. Retrieved January 25, 2019.
- Smith, Sean (June 22, 2006). "Company Profile: Sonic Team". Retro Gamer. Vol. 3 no. 26. Imagine Publishing. p. 27.
- Fahs, Travis (May 29, 2008). "Sonic X-treme Revisited". IGN. Ziff Davis. Archived from the original on July 12, 2017. Retrieved November 11, 2017.
- "The Making of Sonic X-treme". Edge: 100–103. July 2007.
- Buchanan, Levi (February 2, 2009). "What Hath Sonic Wrought? Vol. 10 – Saturn Feature at IGN". IGN. Ziff Davis. Retrieved July 23, 2012.
- Towell, Justin (June 23, 2012). "Super-rare 1990 Sonic The Hedgehog prototype is missing". GamesRadar. Future Publishing. Archived from the original on March 24, 2016. Retrieved March 4, 2014.
The reason why there wasn't a Sonic game on Saturn was really because we were concentrating on NiGHTS. We were also working on Sonic Adventure—that was originally intended to be out on Saturn, but because Sega as a company was bringing out a new piece of hardware—the Dreamcast—we resorted to switching it over to the Dreamcast, which was the newest hardware at the time. So that's why there wasn't a Sonic game on Saturn. With regards to X-Treme, I'm not really sure on the exact details of why it was cut short, but from looking at how it was going, it wasn't looking very good from my perspective. So I felt relief when I heard it was cancelled.
- "Whatever Happened To... Sonic X-treme". Retro Gamer. No. 22. Imagine Publishing. March 2006. pp. 36–38.
- Hunt, Stuart; Jones, Darran (December 2007). "The Making Of... Nights". Retro Gamer (45): 26–33.
- Williamson, Coliun (November 14, 2014). "Sonic Jam overview". AllGame. All Media Network. Archived from the original on November 14, 2014. Retrieved November 14, 2016.
- The Secrets of Sonic – Director's Commentary with Takashi Iizuka. Tokyo: Sega. June 5, 2003.
- "Sega Saturn Magazine Interview with Yuji Naka". Sega Saturn Magazine (36). October 8, 1998. Retrieved November 11, 2017.
- Sonic Team (December 23, 1998). Sonic Adventure. Sega. Level/area: Credits.
- "Sega Unveils Sonic Adventure". News. Edge. No. 63. Bath: Future plc. October 1998. pp. 6–7. ISSN 1350-1593.
- "Mini Making of... Sonic Adventure". Retro Gamer (91): 34–35. June 23, 2011.
- "Profile: Yuji Naka" (PDF). Official Dreamcast Magazine (1): 35. September 1999. Retrieved January 26, 2018.
- GamesTM (2010). "Behind The Scenes Sonic Adventure". Retro Volume 3. Bournemouth: Imagine Publishing. pp. 60–63. ISBN 978-1-90607-856-0.
- Cook & Becker (April 7, 2017). "How Sega moved Sonic from 2D to 3D". Polygon. Vox Media. Archived from the original on July 5, 2017. Retrieved November 11, 2017.
- Betker, Gerjet (July 20, 2011). "Die Sonic-Fans nie wieder enttäuschen!". Gamers Global (in German). Jörg Langer. Archived from the original on March 1, 2012. Retrieved February 2, 2014.
- IGN Staff (June 4, 2001). "Interview With Sonic Adventure 2 Director Takashi Iizuka". IGN. Ziff Davis. Archived from the original on March 23, 2016. Retrieved November 13, 2017.
- Sonic Generations Official Strategy Guide. BradyGames. November 1, 2011. p. 206. ISBN 978-0744013429.
- ソニック役でお馴染み、金丸淳一さん声優30周年！ オリジナルアルバム再販記念ロングインタビュー (in Japanese). Animate Times. March 21, 2016. Retrieved November 14, 2018.
- Barratt, Charlie. "Characters you never knew had the same voice actor". GamesRadar. Future plc. Archived from the original on October 21, 2016. Retrieved November 11, 2017.
- Casey (June 24, 2016). "Sega Explains How Dr. Robotnik Came To Be Called Eggman". Siliconera. Curse, Inc. Retrieved March 15, 2018.
- Mandelin, Clyde (June 15, 2013). "How Dr. Robotnik Turns into Dr. Eggman in Japanese Sonic Adventure". Legends of Localization. Retrieved October 7, 2018.
- Donlan, Christian (2010). 1001 Video Games You Must Play Before You Die. Universe Publishing. ISBN 978-0-7893-2090-2.
- "Afterthoughts: Sonic Heroes – A candid chat with Sonic Team's lord of the rings". Electronic Gaming Monthly. Ziff Davis. Archived from the original on March 30, 2004. Retrieved November 18, 2017.
- "Digi-Log Conversation Sonic Adventure O.S.T. Side-A". sonic.sega.jp (in Japanese). Sega. Archived from the original on June 16, 2016. Retrieved November 13, 2017.
- "Digi-Log Conversation Sonic Adventure O.S.T. Side-B". sonic.sega.jp (in Japanese). Sega. Archived from the original on August 18, 2016. Retrieved November 13, 2017.
- Senoue, Jun; Iizuka, Takashi (2018), "Interview with Takashi Iizuka & Jun Senoue", Sonic Adventure Official Soundtrack Vinyl Edition, Brave Wave Productions
- Sonic Team Q&A 2011 (YouTube). The Sonic Show. July 2, 2012. (Event occurs at 12:50.)
- "Digi-Log Conversion". Sonic Channel (in Japanese). Sega. January 20, 1999. Archived from the original on August 16, 2016. Retrieved November 13, 2017.
- Sega (May 18, 2011). "Sonic Adventure Original Soundtrack 20th Anniversary Edition". iTunes. Apple Inc. Archived from the original on November 7, 2017. Retrieved November 11, 2017.
- Sega (September 10, 2014). "Sonic Adventure (Original Soundtrack), Vol. 1". iTunes. Apple Inc. Archived from the original on November 14, 2017. Retrieved November 11, 2017.
- Sega (September 10, 2014). "Sonic Adventure Original Soundtrack vol.2". iTunes. Apple Inc. Archived from the original on November 14, 2017. Retrieved November 11, 2017.
- Leack, Jonathan (January 25, 2017). "Sonic the Hedgehog Heads To Spotify As SEGA Adds Thousands Of Tracks". Game Revolution. CraveOnline. Archived from the original on November 14, 2017. Retrieved November 11, 2017.
- "The legendary soundtracks for SONIC ADVENTURE & SONIC ADVENTURE 2 are coming to vinyl this Winter!". Brave Wave Productions. Retrieved April 4, 2018.
- "The Red-Hot Rumours Division!". Computer and Video Games (15). July 1997.
- ドリームキャスト. Sonic Channel (in Japanese). Sega. Archived from the original on December 7, 2015. Retrieved November 11, 2017.
- "Sonic Under the Tree". GameSpot. December 23, 1998. Archived from the original on June 9, 2000. Retrieved September 20, 2019.
- "Sonic Adventure – Dreamcast". IGN. Ziff Davis. Archived from the original on October 20, 2015. Retrieved August 7, 2017.
- "Dreamcast Special: Sonic Adventure". Computer and Video Games (215): 60–61. September 1999. Archived from the original on June 20, 2017. Retrieved November 12, 2017.
- Gantayat, Anoop (August 28, 1999). "Sonic Adventure US Shocker". IGN. Ziff Davis. Archived from the original on February 23, 2014. Retrieved January 19, 2013.
- Gantayat, Anoop (August 24, 1999). "Sonic Adventure: Internet Gaming!". IGN. Ziff Davis. Archived from the original on February 23, 2014. Retrieved January 19, 2013.
- "Sonic Adventure International – Dreamcast". IGN. Ziff Davis. Archived from the original on July 28, 2017. Retrieved November 12, 2017.
- Gantayat, Anoop (July 15, 1999). "Sonic Adventure: Limited Edition Quick Look". IGN. Ziff Davis. Archived from the original on October 26, 2014. Retrieved October 24, 2014.
- IGN staff (July 15, 1999). "A Sit-down with Sonic Adventure: LE". IGN. Ziff Davis. Archived from the original on October 26, 2014. Retrieved October 24, 2014.
- IGN staff (June 29, 1999). "Sega Releases Full Details of Rental Program". IGN. Ziff Davis. Archived from the original on October 26, 2014. Retrieved October 24, 2014.
- Gilbert, Henry (August 1, 2014). "15 esoteric game-to-anime adaptations worth discovering". GamesRadar+. Retrieved October 31, 2014.
- Lee, Patrick (September 30, 2015). "A hedgehog for all seasons: Our guide to 20 manic years of Sonic cartoons". The A.V. Club. Retrieved October 30, 2019.
- Soete, Tim (September 10, 1999). "Some Dreamcast games not working". ZDNet. Retrieved October 18, 2021.
- "Dreamcast: Huge sales but plagued by disc problems". ZDNet UK. September 13, 1999. Retrieved October 18, 2021.
- "Sonic Adventure for Dreamcast". GameRankings. CBS Interactive. Archived from the original on March 3, 2009. Retrieved November 13, 2017.
- "Sonic Adventure". Testscreen. Edge. No. 68. Bath: Future plc. February 1999. pp. 70–73. ISSN 1350-1593.
- Fischer, Blake (October 1999). "Finals" (PDF). Next Generation. Vol. 2 no. 2. Imagine Media. p. 104=105.
- "100 Best Games Ever: Sonic Adventure". Computer and Video Games. No. 240. November 2001. p. 60. Retrieved January 23, 2018.
- Boutros, Daniel (August 4, 2006). "A Detailed Cross-Examination of Yesterday and Today's Best-Selling Platform Games". Gamasutra. UBM plc. Archived from the original on July 2, 2016. Retrieved November 12, 2017.
- "Sonic Adventure" (PDF). Arcade (1): 23. December 1998.
- "Sonic Adventure". Hyper. No. 65. Next Publishing Pty Ltd. March 1999. p. 18.
- Sutton, Adam (March 3, 2011). "Videogame Voice Acting: So Bad, It's Good". IGN. Ziff Davis. Archived from the original on September 14, 2016. Retrieved November 11, 2017.
- Noble, McKinley (May 6, 2009). "The 20 Best Platformers: 1989 to 2009". GamePro. International Data Group. Archived from the original on January 28, 2010. Retrieved February 21, 2018.
- DeMaria, Rusel, and Johnny L. Wilson (2004), High Score!: The Illustrated History of Electronic Games, McGraw-Hill/Osborne, p. 312. ISBN 0072224282.
- Cundy, Matt; Houghton, David; Irvine, Nathan; Towell, Justin (June 23, 2012). "Top 7... horrendously buggy games we loved anyway". GamesRadar. Future Publishing. Archived from the original on May 2, 2014. Retrieved May 1, 2014.
- "Sonic Adventure". Computer and Video Games (209): 20. April 1999.
- Variety Staff (May 9, 2000). "Blockbuster Entertainment Award winners". Variety. Retrieved September 22, 2021.
- "GameSpot Console Platform Game of the Year 1999 – Archived from original videogames.com web site". March 1, 2000. Archived from the original on March 1, 2000. Retrieved September 22, 2021.
- Ahmed, Shahed (January 31, 2001). "Sega announces drastic restructuring". GameSpot. CBS Interactive. Archived from the original on July 4, 2017. Retrieved November 2, 2017.
- IGN Staff (January 23, 2001). "Sega Confirms PS2 and Game Boy Advance Negotiations". IGN. Ziff Davis. Archived from the original on March 23, 2016. Retrieved November 2, 2017.
- Stratton, Bryan (June 17, 2003). Sonic Adventure DX: Prima's Official Strategy Guide. Prima Games. ISBN 978-0761542865.
- "Sonic Adventure DX: Director's Cut for GameCube". GameRankings. CBS Interactive. Archived from the original on June 30, 2017. Retrieved November 14, 2017.
- Coles, Michael (June 28, 2003). "Sonic Adventure DX Director's Cut". Nintendo World Report. Billy Berghammer. Archived from the original on February 28, 2014. Retrieved November 13, 2017.
- Barnholt, Ray (September 14, 2010). "Sonic Adventure XBLA Review". 1UP.com. Ziff Davis. Archived from the original on March 19, 2013. Retrieved November 12, 2017.
- Sega (March 4, 2011). "Sonic Adventure DX". Steam. Valve. Archived from the original on September 29, 2017. Retrieved November 12, 2017.
- "Sonic Adventure – PlayStation 3". IGN. Ziff Davis. Archived from the original on July 12, 2017. Retrieved November 12, 2017.
- Sega (September 11, 2012). "Sonic Adventure DX Upgrade". Xbox Marketplace. Microsoft. Archived from the original on November 14, 2014. Retrieved November 12, 2017.
- Buchanan, Levi (March 9, 2011). "Dreamcast Collection Review". IGN. Ziff Davis. Retrieved April 4, 2018.
- Pereira, Chris (September 28, 2017). "Two More Xbox One Backwards Compatible Games Now Available". GameSpot. CBS Interactive. Archived from the original on October 30, 2017. Retrieved November 13, 2017.
- "Sonic Adventure for Xbox 360 Reviews". Metacritic. CBS Interactive. Archived from the original on September 9, 2010. Retrieved November 13, 2017.
- Gies, Arthur (September 23, 2010). "Sonic Adventure Review". IGN. Ziff Davis. Archived from the original on March 6, 2013. Retrieved November 13, 2017.
- Legarie, Destin (September 27, 2010). "Review: Sonic Adventure (XBLA)". Destructoid. Enthusiast Gaming. Archived from the original on February 25, 2016. Retrieved November 13, 2017.
- Cocke, Taylor (June 21, 2012). "Silver Lining: Sonic the Hedgehog and a history of disappointment". Joystiq. AOL. Archived from the original on April 20, 2014. Retrieved April 19, 2014.
- GamesRadar Staff (May 19, 2017). "The best Sonic games of all time". GamesRadar. Future plc. Retrieved April 7, 2018.
- USgamer Team (August 8, 2017). "Gotta Go Fast: Ranking All of The Sonic The Hedgehog Games". USgamer. Gamer Network. Retrieved April 7, 2018.
- Stewart, Zolani (August 4, 2014). "Where Sonic The Hedgehog Went Wrong". Kotaku. Gawker Media. Archived from the original on December 13, 2017. Retrieved June 30, 2018.
- Fahey, Rob (November 24, 2006). "Sonic The Hedgehog". Eurogamer. Gamer Network. Archived from the original on March 1, 2017. Retrieved November 13, 2017.
- Lotito, Tom (May 4, 2012). "TGS 2006: Sonic The Hedgehog Impressions". GameZone. GameZone Next. Archived from the original on November 14, 2017. Retrieved November 13, 2017.
- Towell, Justin (October 31, 2011). "Sonic Generations review". GamesRadar. Future Publishing. Archived from the original on February 10, 2017. Retrieved October 2, 2017.
- Sterling, Jim (October 31, 2011). "Review: Sonic Generations". Destructoid. Enthusiast Gaming. Archived from the original on November 29, 2016. Retrieved October 3, 2017.
- Whitehead, Dan (December 9, 2011). "Sonic Generations 3DS Review". Eurogamer. Gamer Network. Archived from the original on March 30, 2016. Retrieved October 3, 2017.
- DeFreitas, Casey (June 15, 2017). "E3 2017: Chao Will Not Be Featured in Sonic Forces". IGN. Ziff Davis. Retrieved January 31, 2018.
- Sonic Team (December 4, 2003). Sonic Battle (Game Boy Advance). Sega.
- Newton, James (October 16, 2009). "Mario & Sonic at the Olympic Winter Games Review – Wii". Nintendo Life. Gamer Network. Retrieved February 21, 2018.
- Sterling, Jim (September 29, 2008). "Destructoid review: Sonic Chronicles: The Dark Brotherhood". Destructoid. Enthusiast Gaming. Retrieved February 2, 2010.
- Shea, Brian (May 16, 2016). "The 10 Worst Characters In Sonic History". Game Informer. GameStop. Retrieved December 11, 2017.
- Sterling, Jim (June 23, 2012). "The 10 worst Sonic friends". GamesRadar. Future Publishing. Archived from the original on November 1, 2013. Retrieved February 2, 2014.
- "The best and worst Sonic characters". Official Nintendo Magazine. Future Publishing. May 29, 2013. Archived from the original on October 29, 2013. Retrieved February 2, 2014.
- 1UP Staff. "Least Popular Character Tournament". 1UP.com. Ziff Davis. Archived from the original on March 19, 2013. Retrieved February 2, 2014.
- Justice, Brandon (October 4, 1999). "Sega Speaks Out on Sonic Adventure Follow-up". IGN. Ziff Davis. Archived from the original on June 4, 2016. Retrieved November 13, 2017.
- Gantayat, Anoop (June 30, 2000). "First Direct Feed Footage of Sonic Adventure 2". IGN. Ziff Davis. Archived from the original on June 4, 2016. Retrieved November 13, 2017.
- "Sonic Adventure 2 – Dreamcast". IGN. Ziff Davis. Archived from the original on January 28, 2017. Retrieved November 13, 2017.
- "Sonic Adventure 2 for Dreamcast Reviews". Metacritic. CBS Interactive. November 25, 2014. Archived from the original on December 27, 2014. Retrieved February 21, 2018.
- Robinson, Andy (April 9, 2008). "Sonic Unleashed "has no relation" to Sonic 360/PS3". Computer and Video Games. Future Publishing. Archived from the original on April 12, 2008. Retrieved April 13, 2008.
- Frank, Allegra (September 19, 2017). "Sonic Adventure 3 may never happen". Polygon. Vox Media. Retrieved November 16, 2017.
- Workman, Robert (December 31, 2018). "'Sonic Adventure' Remake Definitely of Interest, Says Studio Head". ComicBook.com. Retrieved January 1, 2019.
- Jones, Tim. "Sonic X". THEM Anime. Archived from the original on September 22, 2003. Retrieved April 6, 2014.
- Bollers, Karl (December 1999). "The Discovery: A Sonic Adventure Tie-In". Sonic the Hedgehog. 1 (79).
|Wikiquote has quotations related to: Sonic Adventure|
|Wikimedia Commons has media related to Sonic Adventure.|