Sonic the Hedgehog 2
|Sonic the Hedgehog 2|
European box art
Sega Technical Institute
|Series||Sonic the Hedgehog|
Sonic the Hedgehog 2[a] is a platform video game developed and published by Sega for the Sega Genesis console. It was released worldwide in November 1992. The game is the second main entry in the Sonic the Hedgehog series. In the game, protagonist Sonic the Hedgehog and his sidekick Miles "Tails" Prower must stop series antagonist Dr. Ivo Robotnik from stealing the Chaos Emeralds to power his space station, the Death Egg.
Development of Sonic the Hedgehog 2 began at the end of 1991, with both Japanese and American staff, from Sonic Team and Sega Technical Institute respectively, contributing to development. As with the original game, the soundtrack was composed by Dreams Come True songwriter Masato Nakamura. Upon release, the game was a critical and commercial success, selling over six million copies, making it the second-best-selling Genesis game behind the original Sonic the Hedgehog. It has since been released on several compilations and downloads for various platforms, which were also generally positively received. A remastered version, developed using the Retro Engine, was released on iOS and Android devices in December 2013. Two direct sequels, Sonic the Hedgehog 3 and Sonic & Knuckles, were released in 1994.
The game's premise is similar to that of the original Sonic the Hedgehog. Sonic's nemesis, Dr. Ivo Robotnik, is planning world domination through the power of the Chaos Emeralds and an army of robots powered by trapped animals. Specific to this game, he is additionally constructing an armored space station known as the Death Egg (a parody of the Death Star), also for the means of world domination.
The events of the game see Sonic and Tails chasing Robotnik through West Side Island, and eventually up to the Death Egg, pursuing him with Tails' biplane, the Tornado. The plane is damaged after being shot at, but Sonic still manages to infiltrate the Death Egg, alone. Once there, he battles a robotic imposter before taking on Robotnik, who is piloting a giant mech. Sonic manages to defeat the robot and it explodes, damaging the Death Egg and knocking it out of orbit. Sonic falls to the ground and is saved by Tails in the Tornado. If the player has collected all of the Chaos Emeralds, Sonic, in his Super Sonic form, flies alongside it.
Sonic the Hedgehog 2 is a 2D, side-scrolling platform game. The game stars Sonic the Hedgehog and his sidekick, Miles "Tails" Prower, who is described as having idolized Sonic as a child and wanting to keep up with him. At the game's start, the player can select to either play as Sonic, Tails, or both. The difference between the two is purely cosmetic; the two both have identical abilities. In the latter mode, players control Sonic while Tails runs along beside him. A second player can join in at any time and control Tails separately. The game takes place over a series of levels, each divided into one, two, or three acts with a boss fight with Robotnik at the end of the last act. Certain levels have features that are unique to them; for example, Emerald Hill has corkscrew-like loops, and Chemical Plant has boost pads that instantly put Sonic at his top speed. The character can jump on enemies to defeat them; the game also introduces a new move, the "spin dash" or "Super Dash Attack", by which the player curls in a ball and spins while stationary, resulting in a speed boost. When the player is attacked by an enemy without rings, is crushed, falls off-screen, or exceeds the act's ten-minute limit, they lose a life and return to the most recently passed checkpoint. Dying with zero lives gives the player a game over.
When the player collects at least 50 rings and passes a checkpoint, they can warp to a "special stage". In these stages, the player runs through a pseudo-3D half-pipe course, collecting rings and dodging bombs. A set amount of rings must be collected to pass through each of three checkpoints and in turn to obtain the emerald itself. If Sonic collides with a bomb, he loses ten rings and is immobilized momentarily. The stages rise in difficulty, and the player cannot enter any stage without passing the previous one. After finishing, the player is transported back to the star post they used to enter the special stage, with their ring-count reset to zero. When all Emeralds have been collected, if the player chose Sonic, he has the ability to turn into Super Sonic, which requires 50 rings or more. Super Sonic is yellow and invincible to enemy attacks, and his speed, acceleration, and jump height are increased as well. However, he loses one ring per second and reverts to being regular Sonic when all of his rings are gone.
The game also has a competitive mode, where two players compete against each other to the finish line, as either Sonic or Tails, in a split-screen race through three of the regular levels and a special stage. After one player finishes one of the regular levels, the other player must finish the zone within 60 seconds, or the level ends instantly. In the regular levels, players are ranked in five areas (score, time, rings held at the end of the level, total rings collected, and the number of item boxes broken). The player with wins in the most number of categories wins the level. In the Special Stage, players compete to obtain the most rings. The mode ends when all stages have been completed, or if a player loses all their lives, in which their opponent will automatically win.
Knuckles the Echidna in Sonic the Hedgehog 2
Sonic & Knuckles was released in 1994, two years after Sonic 2. The Sonic & Knuckles game cartridge features a special "lock-on" port into which the player can insert other Genesis cartridges. Attaching Sonic 2 unlocks Knuckles the Echidna in Sonic the Hedgehog 2, a variation of Sonic 2 whereby the player plays as Knuckles the Echidna, a character introduced in Sonic the Hedgehog 3 and not playable until Sonic & Knuckles. Though the game is largely identical to Sonic the Hedgehog 2, Knuckles is able to glide and climb walls, allowing him access to areas previously inaccessible to Sonic or Tails. However, he cannot jump as high, making some parts of the game, such as certain boss fights, more difficult. In addition, fewer rings are needed to progress in special stages and the score no longer resets. The two-player mode is removed.
Following the release of the original Sonic the Hedgehog, creator Yuji Naka quit Sega due to disagreements over its corporate policies. Mark Cerny, who had recently founded Sega Technical Institute (STI) in the American state of California, met with Naka in Japan and offered him a higher salary and more creative freedom if he joined STI. Naka agreed, and Hirokazu Yasuhara, the lead level designer of Sonic the Hedgehog, also decided to move to STI. Yasuhara had been assigned to help Cerny establish STI in 1990, but the outbreak of the Gulf War delayed his move to the United States by three months, during which he joined Sonic Team and became part of the Sonic project.
Development of Sonic 2 began in November 1991, two months later than Cerny had intended because Sega of America initially felt it was too soon for a sequel. Both American and Japanese Sonic Team staff contributed to development; art director Tim Skelly designed the appearance of the game's pseudo-3D special stages, based on a tech demo created by Naka. The special stages were created out of pre-rendered 3D polygons, video of which was compressed and halved, both vertically and horizontally, to fit in the game cartridge. Sonic 2 also introduced Sonic's sidekick, a two-tailed fox that could fly named Tails, inspired by Japanese folklore about the kitsune and created by level artist Yasushi Yamaguchi. Sega of America objected to the character's name, Miles Prower (a pun on "miles per hour"), so he was given the nickname Tails as a compromise. Masaharu Yoshii served as the game's director. The staff increased the speed of Sonic the Hedgehog 2 compared to the first game.
Sonic 2 is believed to have been planned to have time travel aspects and was originally developed alongside Sonic the Hedgehog CD as the same game, but Sonic CD eventually became its own game over time. A demonstration cartridge of Sonic 2 was stolen at a New York City toy show early in 1992, which was later attributed to a lack of security. The prototype ROM was rediscovered by a fan named Simon Wai on a Chinese website, and features playable sections of two cut levels from the final release of the game: "Wood Zone" and "Hidden Palace Zone". The "Hidden Palace Zone" was in the game from the start, but removed because of a lack of time and capacity.
The basic idea was about the same as it was in Sonic & Knuckles. You'd encounter the stage through normal play by collecting the emeralds. The idea behind the stage was, "Where do the Chaos Emeralds come from?" That's where Sonic was originally supposed to be granted his Super Sonic powers. We finally were able to use it in S&K, though it wound up being quite different from what we had planned in Sonic 2. But even from Sonic 1 we'd been throwing around those sorts of ideas. Still, when we were running out of time, we looked over things quickly trying to figure out what to dump ... and CHOP went the Hidden Palace. There's simply no way we could have thrown that in by the deadline at the rate we were going.— Yuji Naka, on the intended purpose of the Hidden Palace stage
Although a level sharing the same name appeared in Sonic & Knuckles, the original version of Hidden Palace was left unfinished until the remastered iOS port was released in December 2013, which features a redesigned version of the level as an optional stage. Sega also provided some magazines with mockup images that showed another scrapped level, the desert-themed Dust Hill Zone, and the stolen 1992 prototype features an unused level slot titled "Genocide City". Naka has also alluded to another scrapped level in the Sonic Jam Official Strategy Guide, explaining why the Metropolis Zone had three parts to it, while every other level only had two: "Due to problems with the story, Act 3 was going to be a different Zone that would only appear once, but since it was cut, we still wanted to have something after Act 2. So that's why there are three acts in this one. We had already finished the map, and it would have been a shame to waste it, so this is what we went with."
Sonic the Hedgehog 2's music, like the previous game, was composed by Masato Nakamura, bassist and lead songwriter of the J-pop band Dreams Come True. The music began early on in development with only concept images for Nakamura's reference, but having a previous game meant he had experience with creating music for the Genesis and began taking a similar approach to the first game. Nakamura treated Sonic the Hedgehog 2 as a film and designed the music around the atmosphere that he felt from the images of the stages. Except for the graphics and some discussion with Sonic Team, Nakamura was given freedom over the music creation which he believes was the reason why he was able to create "such melodic tunes and unusual rhythm patterns".
Nakamura created the music while he was recording with Dreams Come True in London, working on their fifth album The Swinging Star. As a gift to Sonic Team, Masato produced an alternate version of the ending theme with Dreams Come True, which was included in the album they were recording at the time. In 2011, the stage music from Chemical Plant and Casino Night Zone were remixed by Sega for use in Sonic Generations.
Later in October of the same year, a three-disc compilation of the music from Sonic the Hedgehog and Sonic the Hedgehog 2 was released in Japan. Alongside music from the game, the compilation includes comments by Yuji Naka and an interview with Nakamura. The first disc contains original tracks from both games, and the second contains Nakamura's demo recordings produced during the games' development. The third disc contains "Sweet Sweet Sweet" by Dreams Come True, its English-language version "Sweet Dream", and 2006 remixes of both songs by singer Akon which were used in Sonic the Hedgehog (2006).
Sega launched a $10 million advertising campaign for Sonic the Hedgehog 2's release. Sega sought a global release date to make the game available in all stores on the same day, a fairly novel concept at the time. This required Sega to reconfigure its distribution system to ensure that games were available in all major stores. The release date, Tuesday, November 24, 1992 was marketed as "Sonic 2s day". While the Genesis release in North America and the Mega Drive release in Europe both released the game on this day, Sega made the game available a few days before in Japan on November 21, 1992. 400,000 copies of Sonic 2 were sold in the first seven days after release and over 6 million in the lifespan of the console.
Alternate versions and ports
A version of the game for the Sega Master System and Game Gear was developed by Aspect. Though based on the original game of the same name, it is a distinct game, with different level designs and a different plot, and this version, unlike the 16-bit release, does not have the spin dash, which led it to being thought to be made before the Sega Genesis version.
A remastered mobile port was released for iOS, Android, and Windows Phone devices on December 12, 2013. This version was developed from scratch by Christian "Taxman" Whitehead and Simon "Stealth" Thomley using the Retro Engine previously used in the 2011 remaster of Sonic the Hedgehog CD. This version adds several enhancements, such as widescreen graphics, Knuckles as a playable character, time and boss attack modes, online multiplayer, additional multiplayer stages, and the previously unreleased Hidden Palace Zone. Additionally, Tails is given his abilities from Sonic the Hedgehog 3, and the remaster features a post-credits scene which depicts the Death Egg crash-landing on Angel Island. This version was received positively, with Shaun Musgrave of TouchArcade declaring it the "definitive version" of the game. The iOS version was updated in 2016, adding compatibility for Apple TV.
Compilations that include the game are Sonic Compilation (1995) for the Sega Mega Drive/Genesis; Sonic Jam (1997) for the Sega Saturn; Sonic Mega Collection (2002) for the Nintendo GameCube; Sonic Mega Collection Plus (2004) for the PlayStation 2, Xbox, and PC; Sega Genesis Collection (2006) for the PlayStation 2 and PlayStation Portable; Sonic's Ultimate Genesis Collection (2009) for the Xbox 360 and PlayStation 3; and Sonic Classic Collection (2010) for the Nintendo DS.
The game was made available for download on Wii's Virtual Console on June 11, 2007, PlayStation 3 via the PlayStation Network on April 19, 2011, and Xbox 360 via Xbox Live Arcade, the latter having enhancements such as online leaderboards, achievements, and online play. Various mobile phone versions exist as well, including the iOS release. The game was released as part of the Nintendo 3DS 3D Classics line in Japan on July 22, 2015, with a release in North America and Europe initially slated for September 2015, before being pushed back to October 8.
Due to the popularity of its predecessor, Sonic the Hedgehog 2 already had an established fanbase anticipating its release. The game received critical acclaim upon release and was a best seller in the UK charts for 2 months. As of 2006, the game has sold over 6 million copies, making it the second best-selling game for the Sega Genesis (after the original Sonic the Hedgehog).
Reviewers praised the game for its large levels, colorful graphics and backgrounds, increased cast of characters, enemies, and music. GameSpot stated that "time may have eroded Sega's prominence, but it hasn't done much to diminish how sweet Sonic the Hedgehog 2 is," and, along with other reviewers, commented on how it is still a fun game to play. Electronic Gaming Monthly awarded it as the best Sega Genesis game of 1992. In 2000, Game Informer ranked Sonic 2 number 61 on its "Top 100 Games of All Time" list, calling it "the most challenging and finely polished Sonic the Hedgehog title." Mega placed the game at #36 in their "Top Sega Mega Drive Games of All Time" list. Critics also enjoyed the faster gameplay the game offered in comparison to its predecessor, as well as its new features. Lucas Thomas of IGN praised the new "Spin-Dash" ability, which would prepare Sonic to launch at a faster speed. Thomas also noted that the levels of Sonic 2 were designed to showcase the character's speed, and was less a "platform-jumping game" than a "platform-running" game, in slight contrast to its predecessor.
The game's main criticisms were the two player mode, a new introduction to the series. Reviewers criticized the mode's noticeable slowdown and prominent flickering, and the squashed play area for each player. However, Lucas Thomas praised the innovation of the new two player mode, quipping that "Mario and Luigi could never run competitively through the same levels, at the same time". William Burrill of the Toronto Star described the two player racing mode as the "only part of the game that can be faulted," citing that the mode and its split screen view "squeezes the graphics, plumps up the characters and slows down the action."
Sonic 2's financial success was a major factor in Sega catching up to Nintendo in the early-1990s console wars. It brought their market share up to 50% within six months of its release. Tails, whom Sonic the Hedgehog 2 introduced, would go on to become one of the most prominent and frequently recurring characters in the series, appearing and acting as Sonic's sidekick in most of the franchise's media, including in recent games such as Sonic Colors, Sonic Generations, and Sonic Lost World in which most of the recurring cast does not appear or is relegated to minor roles. Furthermore, Sonic the Hedgehog 2's popularity managed to extend to various merchandise such as comic books (the well-received fortnightly Sonic the Comic), a television series, and a sequel, Sonic the Hedgehog 3, which received similar acclaim.
For Sonic's 20th anniversary, Sega released Sonic Generations, a game that remade aspects of various past games from the franchise. The PlayStation 3, Xbox 360, and PC versions contained a remade "Chemical Plant" level. It also contained a remake of the final boss fight, the Death Egg Robot, as the Classic Era boss of the game. Separately, the Nintendo 3DS version of the game contained a remake of the "Casino Night" level. A "Casino Night" themed pinball minigame was made available for download as a pre-order bonus for the console versions at GameStop. A remade version of Chemical Plant also appears in the 2017 game Sonic Mania.
- Biddle, Frederic M. (1992-12-08). "Sega vs. Nintendo: The Rematch". The Boston Globe. p. Economy 43.
- ソニック・ザ・ヘッジホッグ2 （マスターシステム版）. Famitsu (in Japanese). Famitsu Japan. Retrieved 2014-11-17.
- Sonic the Hedgehog 2 (Genesis) instruction manual, p. 4.
- Creegan, Dermot. "Casual Monday: Sonic the Hedgehog 2". Hardcore Gamer. Disqus. Retrieved 2014-11-16.
- Lucas M., Thomas (2007). "IGN's Sonic the Hedgehog 2 Review". IGN. Ziff Davis. Retrieved 2007-10-21.
- Sonic the Hedgehog 2 (Genesis) instruction manual, p. 3.
- Sonic the Hedgehog 2 (Genesis) instruction manual, p. 8.
- Sonic the Hedgehog 2 (Genesis) instruction manual, p. 7.
- Sonic the Hedgehog 2 (Genesis) instruction manual, p. 6.
- Sonic the Hedgehog 2 (Genesis) instruction manual, p. 9.
- Sonic the Hedgehog 2 (Genesis) instruction manual, p. 18.
- Nelson, Jared. "A Guide to 'Sonic The Hedgehog' Version 2.0's Hidden Level-select, Debug Mode, and Many More Secrets". TouchArcade. Arnold Kim. Retrieved 2014-11-16.
- Sonic the Hedgehog 2 (Genesis) instruction manual, p. 17.
- Sonic the Hedgehog 2 (Genesis) instruction manual, pp. 19–20.
- Newton, James. "Sonic & Knuckles "lock-on" review". NintendoLife. GamesIndustry.biz. Retrieved 2014-11-14.
- Horowitz, Ken (2007-06-11). "Developer's Den: Sega Technical Institute". Sega-16. Retrieved 2014-07-11.
- "The Essential 50 Part 28 - Sonic the Hedgehog". 1UP.com. Ziff Davis. Archived from the original on 2011-06-22. Retrieved 2014-07-21.
- "Sonic's Architect: GI Interviews Hirokazu Yasuhara". Game Informer. Vol. 13 no. 124. August 2003. pp. 114–116.
- Thomason, Steve (January 2007). "Birth of a Hedgehog". Nintendo Power. Vol. 20 no. 211. Future Publishing. p. 72.
- "G4 Icons Episode #37: Yuji Naka". YouTube. 2013-04-05. Retrieved 2014-07-11. Event occurs at 8:50.
- 3D Sonic The Hedgehog 2 Included in the SEGA 3D Classics, Sega (October 6, 2015)
- Harris, Blake J. (2014). Console Wars: Sega, Nintendo, and the Battle That Defined a Generation. New York, New York: HarperCollins. pp. 244–247. ISBN 978-0-06-227669-8.
- Sega Video Game Illustrations. Nippon Shuppan Hanbai (Deutschland) GmbH. 1994. p. 50. ISBN 3-910052-50-9.
- "Mega Mouth". Mega. No. 1. October 1992. p. 90.
- DeVries, Jack (2011-12-15). "Sonic CD Review". IGN. Ziff Davis. Retrieved 2014-11-17.
- Kemps, Heidi. "A Quest for the Secret Origins of Lost Video-Game Levels". The Atlantic. Retrieved 11 January 2017.
- "GameSpy: Sega's Yuji Naka Talks!". GameSpy. Retrieved 2007-02-27.
- "Kikizo Games: Features: Sonic Team Interview November 2005 (Page 2)". Kikizo. Kikizo, Ltd. Retrieved 2007-02-27.
- Cook, Dave. "Sonic the Hedgehog 2 Android & iOS remaster restores cut Hidden Palace Zone". VG247. Retrieved 6 January 2017.
- Yuji Naka (2014). "Yuji Naka Game Designer". Sega Mega Drive/Genesis Collected Works (Interview). Read-Only Memory. pp. 278,279. ISBN 978-0-9575768-1-0.
- "GameSpy: Sega's Yuji Naka Talks! - Page 4". GameSpy. Retrieved 2014-01-08.
- Cowan, Danny (2013-12-11). "Remastered Sonic the Hedgehog 2 hits Android, iOS tomorrow with bonus Hidden Palace Zone". Joystiq. AOL. Retrieved 2014-01-08.
- Earth Angel (June 1993). "Sonic Mystery". GamePro. No. 47. IDG. p. 14.
- "Backstage with Sonic the Hedgehog 2". Game Players Sega Guide. Sega: 16. December 1992.
- Sonic Jam: Official Guide ソニックジャムオフィシャルガイド (in Japanese). 1997. ISBN 978-4-797-30337-7.
- Nakamura, Masato (2011), Interview with Masato Nakamura (Album Booklet), DCT Records,
When I started writing the music, "Sonic the Hedgehog 1" was just still images..."Sonic the Hedgehog 2" started off the kind of the same. Just graphics.
- Nakamura, Masato (2011), Interview with Masato Nakamura (Album Booklet), DCT Records,
I wanted to treat 'Sonic the Hedgehog' as a film, my inspiration came from each screenshot, or each stage.
- Nakamura, Masato (2011), Interview with Masato Nakamura (Album Booklet), DCT Records,
There were some briefs and meetings...otherwise, they let me do as I pleased, and gave me the freedom to create music.
- Naka, Yuji (2011), Interview with Yuju Naka (Album Booklet), DCT Records,
Nakamura reoworked the ending theme...info a song entitled "Sweet Sweet Sweet" for inclusion on the Dreams Come True album
- Newton, James. "Sonic Colours Soundtrack Racing to iTunes". NintendoLife. GamesIndustry.biz. Retrieved 2014-11-14.
- Elston, Brett. "Game music of the day: Sonic the Hedgehog 2". GamesRadar. Future US. Retrieved 2014-11-16.
- Gantayat, Anoop. "TGS 2005: Eyes-On Sonic Next-Gen". IGN. Ziff Davis. Retrieved 2014-11-16.
- Good, Owen. "A Look Back at 20 Years of Music History with Sonic". Kotaku. Gawker Media. Retrieved 2014-11-16.
- "POCS-21032~4 | Sonic The Hedgehog 1&2 Soundtrack". VGMdb. Retrieved 2014-01-08.
- "Sonic the Hedgehog 1 & 2 soundtrack - Dreams Come True". Famitsu. Famitsu Japan. Retrieved 2014-11-16.
- Goldfarb, Andrew. "The Greatest Video Game Music 2 Tracklisting Revealed". IGN. Retrieved 27 November 2014.
- Person, Chirs (October 17, 2014). "90s Sonic The Hedgehog CDs Were Pretty Sexual". Kotaku. Retrieved 27 November 2014.
- Harris, Blake J. (2014). Console Wars: Sega, Nintendo, and the Battle That Defined a Generation. New York, New York: HarperCollins. pp. 227–228, 273–275, 372. ISBN 978-0-06-227669-8.
- Boutros, Daniel (2006-08-04). "A Detailed Cross-Examination of Yesterday and Today's Best-Selling Platform Games". Gamasutra. p. 5. Retrieved 2006-12-08.
- The Unknown Gamer (October 1992). "Game Gear Preview: 2". GamePro. No. 39. IDG. p. 114.
- "Sonic 2". Mega Force. Sega (13). January 1993. Retrieved 2012-02-09.
- Christian Whitehead (December 12, 2013). Sonic the Hedgehog 2 (2013). Sega. Level/area: Post-credits scene.
- Musgrave, Shaun. "Sonic The Hedgehog 2 Remastered Review". TouchArcade. Retrieved 31 March 2017.
- Dotson, Carter. "'Sonic the Hedgehog' Remaster Now on Apple TV, 'Sonic 2' and 'Sonic CD' Later This Month". TouchArcade. Retrieved 31 March 2017.
- "Sonic Classics 3 In 1 (Sonic Compilation)". IGN. Ziff Davis. Retrieved 2014-11-16.
- "Sonic Jam - Saturn". IGN. Ziff Davis. Retrieved 2014-11-16.
- Mirabella, Fran (2002-11-02). "Sonic Mega Collection". IGN. Ziff Davis. Retrieved 2014-11-16.
- Goldstein, Hilary (2004-11-03). "Sonic Mega Collection Plus". IGN. Ziff Davis. Retrieved 2014-11-16.
- Goldstein, Hilary (2006-11-15). "Sega Genesis Collection Review". IGN. Ziff Davis. Retrieved 2014-11-16.
- Miller, Greg (2009-02-12). "Sonic's Ultimate Genesis Collection". IGN. Ziff Davis. Retrieved 2014-11-16.
- Harris, Craig (2010-03-05). "Sonic Classic Collection Review". IGN. Ziff Davis. Retrieved 2013-01-27.
- "Virtual Console Mondays: June 11, 2007". Nintendo World Report. Retrieved 2007-10-21.
- "New PlayStation Plus Content For March & April 2011". PlayStation Blog. Sony. 2011-03-02. Retrieved 2014-01-08.
- "Sonic The Hedgehog 2 - Game Detail Page". Xbox.com. Microsoft. Retrieved 2012-02-18.
- Buchanan, Levi (2010-04-20). "Sonic the Hedgehog 2 iPhone Review". IGN. Ziff Davis. Retrieved 2010-04-28.
- "SEGA’s 3D Classics Return this Summer with SEGA Genesis Games for Nintendo 3DS". SEGA. Retrieved 2015-04-14.
- Lamoreux, Ben (2015-09-28). "3D Sonic the Hedgehog 2 is Coming to eShop". Gamnesia. Retrieved 2016-03-13.
- "Sonic the Hedgehog 2". GameRankings. Retrieved 2012-02-03.
- "Sonic the Hedgehog 2". Metacritic. CBS Interactive. Retrieved 2014-11-27.
- "Sonic the Hedgehog 2 Critic Reviews for iPhone/iPad". Metacritic. CBS Interactive. Retrieved 2014-11-27.
- Computer & Video Games, issue 132 (November 1992)
- Electronic Gaming Monthly, 1998 Video Game Buyer's Guide, page 87
- Famitsu, issue 206
- GameFan, volume 1, issue 2 (December 1992), pages 9 & 14-17
- GamePro, issue 42 (January 1993), pages 46-47
- Game Informer, issue 8 (January/February 1993), pages 56-57
- "Classic Reviews: Sonic the Hedgehog 2". Game Informer. Vol. 12 no. 109. May 2002. p. 104.
- Provo, Frank (2007). "Sonic the Hedgehog 2 Review". GameSpot. Retrieved 2007-10-21.
- East, Tom (2008-01-11). "Sonic The Hedgehog 2: The blue hedgehog returns". Official Nintendo Magazine. Archived from the original on 2013-10-31. Retrieved 2012-02-03.
- Bad Influence, issue 2, pages 46-47
- "Review: Sonic the Hedgehog 2". Mean Machines. No. 2. November 1992. pp. 60–3. Retrieved 2012-02-03.
- "Game Review: Sonic the Hedgehog 2". Mega. No. 2. Future Publishing. November 1992. pp. 36–41. Retrieved 2012-02-03.
- "Sonic the Hedgehog 2". Mega Zone (25): 31–33. January 1993.
- "Reviewed: Sonic the Hedgehog 2 (Mega Drive)". Sega Force. Impact Magazines (12): 14–6. December 1992. Retrieved 2012-02-03.
- "Sonic 2". Sega Force Mega. Impact Magazines. 2 (1): 91. August 1993.
- "Buyer's Guide: Best Game of the Year (Genesis)". Electronic Gaming Monthly. 1993.
Sega's famous mascot -- Sonic the Hedgehog is back for his second visit to the Genesis, and this version is hot! With 8 megabits of memory good ol' Sonic has a lot more room to do cool tricks and this is what makes this version stand head and shoulders above all the other Genesis games that came out this year. All in all, Sonic 2 is the best Genesis cart to come along in a long time!
- GameFan, volume 1, issue 3 (January 1993), pages 70-71
- Game Informer, issue 8 (January/February 1993), page 34
- GamePro, issue 44 (March 1993), pages 22-24
- "Official Gallup UK Mega Drive Sales Chart". Mega (6). March 1993.
- "Game Zero's Sonic the Hedgehog 2 Review". Game Zero. 1993.
- "Top 100 Games of All Time". Game Informer. Vol. 11 no. 100. August 2001. p. 28.
- Mega. No. 26. Maverick Magazines. November 1994. p. 74. Missing or empty
- Thomas, Lucas (2007-01-26). "Sonic the Hedgehog VC Review". IGN. Retrieved 2014-11-18.
- Dotson, Carter. "Sonic the Hedgehog 2 Gets the Remastering Treatment, With the Long-Lost Hidden Palace Level Restored". 148Apps. Steel Media Ventures. Retrieved 2014-11-18.
- Thomas, Lucas (2007-06-11). "Sonic the Hedgehog 2 Review". IGN. Retrieved 2014-11-18.
- Burrill, William (1992-12-12). "This Sonic is super, too". Toronto Star. p. F4.
- Claiborn, Samuel. "21 Crazy Facts About Sonic And The Console War He Started". IGN. Ziff Davis. Retrieved 2014-11-16.
- Allan Sugarbaker (24 September 2001). "Interviews: James Wallis". OgreCave.com. Retrieved 22 January 2012.
I teamed up with Carl Sargent and Marc Gascoigne to produce four more Sonic books, novels this time, for Virgin Publishing, under the pseudonym of 'Martin Adams'.
- "FCC 398 Children's Television Programming Report". Licensing.FCC.gov. March 24, 2005. Retrieved 7 July 2012.
- "Sonic the Hedgehog 3". GameRankings. Retrieved 7 February 2012.
- "Sonic Generations overview". IGN. Ziff Davis. Retrieved 2014-11-16.
- Kollar, Phil. "See Sonic's Classic Chemical Plant Zone From Two Perspectives". Game Informer. GameStop. Retrieved 2014-11-16.
- "NYCC 11: Death Egg Robot Boss". GameTrailers. DFY Media. Retrieved 2014-11-16.
- Newton, James. "Sonic Generations Shots Show Casino Night Action". NintendoLife. GamesIndustry.biz. Retrieved 2014-11-16.
- Good, Owen. "Sonic's Casino Night Pinball Comes to PC on Dec. 26". Kotaku. Gawker Media. Retrieved 2014-11-16.
- Bailey, Kat. "Sonic Mania Brings Back the Best Sonic Level Ever". USgamer. Retrieved 8 June 2017.