Sonic the Hedgehog (1991 video game)

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Sonic the Hedgehog
Sonic the Hedgehog 1 Genesis box art.jpg
North American box art
Developer(s) Sonic Team
Publisher(s) Sega
Producer(s) Shinobu Toyoda
Designer(s) Hirokazu Yasuhara[1]
Jina Ishiwatari
Rieko Kodama
Programmer(s) Yuji Naka
Artist(s) Naoto Ohshima
Composer(s) Masato Nakamura
Series Sonic the Hedgehog
Release date(s)
Genre(s) Platform
Mode(s) Single-player
Distribution 4-megabit cartridge

Sonic the Hedgehog (ソニック・ザ・ヘッジホッグ Sonikku za Hejjihoggu?) is a platform video game developed by Sonic Team and published by Sega for the Sega Genesis/Mega Drive. First released in North America, Europe, and Australia on June 23, 1991, the game is the first installment in the Sonic the Hedgehog series, chronicling the adventures of the titular character in his quest to defeat the series' antagonist Dr. Robotnik. The game's story focuses on Sonic's efforts to stop Dr. Robotnik's plans for world domination, release the animals Dr. Robotnik has trapped, and collect six magical emeralds known as the Chaos Emeralds.

Development of Sonic the Hedgehog began in 1990, when Sega ordered its AM8 development team to develop a game featuring a mascot for the company. After a hedgehog was decided on as the main character, the development group was renamed Sonic Team.

Sonic the Hedgehog received positive reviews from critics, who praised the game's visuals and its sense of speed. It was commercially successful, increasing the popularity of the Genesis and establishing Sonic the Hedgehog as the company's mascot. Its success led to the development of subsequent games in the Sonic the Hedgehog series, as well as the creation of a media franchise of spin-off products featuring the character.


In an attempt to steal the six Chaos Emeralds and harness their power, the game's antagonist Dr. Ivo Robotnik ("Dr. Eggman" in the original Japanese release) has trapped the animal inhabitants of South Island in cybernetic shells and metal capsule prisons. The player controls the titular Sonic the Hedgehog, who aims to stop Robotnik's plans by freeing his animal friends and collecting all of the Chaos Emeralds himself.[5] If the player collects all the Chaos Emeralds and completes the game, the most optimal ending sequence is shown. However, if not every Chaos Emerald is collected, a screen shows Robotnik taunting the player.[6]


Sonic the Hedgehog plays as a 2D side-scrolling platformer. The gameplay centers around Sonic's ability to run at high speed through levels that include springs, slopes, high falls, and loop-the-loops.[5] The levels are populated with hazards in the form of robots (named "badniks" in the Western game manuals)[7] that Dr. Robotnik has trapped animals inside; destroying one frees the creature, but is not necessary to complete the game.[8] The player must also avoid touching rows of sharp spikes, falling into bottomless pits, and being crushed by moving walls or platforms, as well as drowning, which can be circumvented by breathing air bubbles periodically released from vents.[9] Sonic's main means of attack is the Spin Attack, in which he curls into a ball and rotates rapidly, damaging enemies and certain obstacles upon collision. This can be performed by jumping in the air or by pressing down on the D-Pad while moving on the ground.[10]

A typical in-game screenshot of Sonic the Hedgehog, taken from its first level, Green Hill Zone.

Scattered around each level map are gold rings.[11] Collecting 100 rings rewards the player with an extra life.[11] Rings act as a layer of protection against hazards: if Sonic holds at least one ring when he collides with an enemy or dangerous obstacle, he will survive.[8] However, all of the rings in his possession will be scattered; they will flicker and disappear in a few seconds if not picked up again. If he is hit without holding any rings, then he loses a life.[12] Shields and temporary invincibility can also be collected to provide additional layers of protection, but certain hazards, such as drowning, being crushed, falling down a bottomless pit or running out of time, will cause Sonic to lose a life regardless of rings or other protection.[5]

A shield powerup similar to that found in the game

The game is split up into six zones—named Green Hill, Marble, Spring Yard, Labyrinth, Star Light, and Scrap Brain[13]—each with its own visual style and enemies. Each zone is split into three acts.[5][9] The player must navigate through each zone to progress. At the end of each zone's third act, the player confronts Dr. Robotnik, who pilots a vehicle, in a boss fight.[11] After completing the sixth zone, the player continues directly to the "Final Zone" for the last encounter with Robotnik.[6] The player is initially given three lives—although powerups and rings give more—which are lost when Sonic collides with hazardous enemies or objects while having no rings, falls off-screen, or exceeds an act's ten-minute time limit. Lampposts that act as checkpoints allow Sonic to return to the most recently activated post when he loses a life.[14] If Sonic loses a life as a result of time running out but has another life, the time will reset to 0:00 when he returns to the checkpoint.[6] If all lives are lost at any point in the game, the "Game Over" screen will appear,[7] at which point the player can return to the beginning of the act with three lives if the player has any continues.[6]

When Sonic reaches the end of Act 1 or Act 2 of a zone while holding at least 50 rings, a large ring appears through which he can jump to enter a "Special Stage." In the Special Stages, Sonic is continually curled up in his Spin Attack animation, and bounces off the bumpers and walls of a 360° rotating maze. In these levels, the player earns a continue with each 50 rings found, but the main goal is to obtain the Chaos Emerald at the end of the maze without colliding with any of the "goal blocks" that instantly end the level.[7][9]


Mario and his popular game series represented a steep hill for Sega to climb to compete with Nintendo – necessitating a memorable mascot character and a technically impressive game.

In 1990, Sega ordered its in-house development studio AM8 to develop a game featuring a mascot for the company; Sega president Hayao Nakayama wanted a character as iconic as Mickey Mouse. Sega had competition with Nintendo and its mascot Mario in mind; Nintendo was dominant at the time—particularly after the release of the incredibly successful Super Mario Bros. 3[15]—and Sega wanted to gain a foothold in the industry.[5] Sega had achieved some success with Genesis ports of its arcade titles, but knew these would not be enough.[15] The origins of Sonic can be traced back to a tech demo created by Yuji Naka, who had developed an algorithm that allowed a sprite to move smoothly on a curve by determining its position with a dot matrix. Naka's original prototype was a platform game that involved a fast-moving character rolling in a ball through a long winding tube, and this concept was subsequently fleshed out with Naoto Ohshima's character designs and levels conceived by designer Hirokazu Yasuhara.[16] Yasuhara originally intended to work on the game for three months, due to his planned move to the United States being delayed by the outbreak of the Gulf War, but became engrossed in the project for nearly one year.[1][16]

AM8 developed ideas for characters while also developing an engine and basic gameplay mechanics. Development shifted toward emphasizing speed, so AM8 eliminated character designs not tied to animals considered to be fast,[5] including kangaroos and squirrels. One idea was a rabbit able to grasp objects with its prehensile ears, but this proved too complicated for the hardware available at the time. The team narrowed its selection further to animals that can roll into balls, with the idea that this would constitute an attacking move. Designers then realized that this alone would not seem dangerous enough, so they focused on two creatures that also have spikes: armadillos and hedgehogs.[15] The hedgehog prevailed, although the armadillo would later become the basis for the character Mighty the Armadillo, who first appeared in SegaSonic the Hedgehog in 1993.[5] The new chararacter was originally named "Mr. Needlemouse", but the 15-member AM8 changed his name to "Sonic" and their studio's to Sonic Team to match.[15] Naka, Oshima, and Yasuhara worked 19 hours a day on the project for a period of several months.[16]

In designing the basic game mechanics, Naka took inspiration from games by Shigeru Miyamoto, which he had grown up playing. He admired the simplicity these games' basic mechanics demonstrated amidst complex environments, so he decided that Sonic would be controlled with only the directional pad for movement and a single button for jumping. At the same time, he wanted his creation to be more action-oriented than the Mario series. Due to the simultaneous need to demonstrate the Genesis' technological prowess, the developing game underwent extensive testing and continual re-designing, a process that took over six months. The developers' efforts did not go unrewarded, however: aside from boasting one of the highest character movement speeds ever seen in a video game, the rotation effect of the special stages had been said to be impossible on the console.[17]

Packaging and release[edit]

Akira Watanabe, the illustrator of the character art featured on the game packaging, said that his sole goal was to depict the characters as "colorful" and to use clear, cutting lines and gradation to "finish them neatly".[18] He said that the developers asked him to create a package design "similar to pop art" and to create the design "without being particular to conventional packages" – something that was instead "original" and "stylish".[18] The game was finally released in the United States on June 23, 1991. Sega of America decided to package the game with American Genesis consoles, replacing Altered Beast. Genesis owners who had purchased their consoles before the pack-in switch were offered free copies of Sonic the Hedgehog, which they could request by mail.[17]


Sonic the Hedgehog 1 & 2 Soundtrack
Soundtrack album by Masato Nakamura
Released October 19, 2011 (Japan)
Recorded DCT Records
Genre Video game soundtrack
Length Total: 02:32:32
Disc 1: 01:07:51
Disc 2: 01:05:15
Disc 3: 00:19:26

Sonic the Hedgehog's music was composed by Masato Nakamura, a member of J-pop band Dreams Come True. The game uses the on-board Yamaha YM2612 and SN76489 programmable sound generators to produce a variety of stereo sound effects and music. The game was originally intended to feature a sound test menu with animations of Sonic breakdancing to the music of a "Sonic Band" consisting of Sharps Chicken on guitar, Max Monkey on bass, Mach Rabbit on drums, and Vector the Crocodile on keyboard. Vector has become a recurring character in the series, being playable and playing a role in the stories of games like Knuckles' Chaotix, Sonic Heroes,[19] and Sonic Free Riders.[20] The development schedule meant that the feature had to be scrapped, and Yuji Naka decided to replace the test with the "Se-ga!" chant used in TV advertisements, which allegedly took up one-eighth of the memory of the 4-megabit cartridge.[19]

On October 19, 2011, twenty years after the game's release, a three-disc compilation of music from Sonic the Hedgehog and Sonic the Hedgehog 2 was released in Japan. The first disc contains original tracks from both games, and the second contains Masato Nakamura's demo recordings.[21] The third disc contains "Sweet Sweet Sweet" by Dreams Come True, its English-language version "Sweet Dream", and 2006 remixes of both songs by Akon. The compilation also includes comments by Yuji Naka and an interview with Masato Nakamura.[22]

Alternate versions and ports[edit]

8-bit version[edit]

A version of Sonic the Hedgehog was developed by Ancient and released for Sega's 8-bit consoles, the Master System and Game Gear, in 1991. The plot and basic gameplay mechanics are similar to those of the 16-bit version, but level themes, and art assets are different.[23] In addition, the level design is flatter, with no vertical loops, and Sonic cannot re-collect his rings after being hit.[24] The game also features a different soundtrack composed by chiptune musician Yuzo Koshiro, which includes his original compositions alongside adaptations of several pieces of music from the 16-bit version.[25] It was the last game ever officially released for the Master System in North America.[26] The Master System version was later re-released for the Wii's Virtual Console service in North America on August 4, 2008[24] and in Europe on August 8.[27] The Game Gear version was included as one of numerous unlockable games in Sonic Adventure DX: Director's Cut for GameCube and Windows,[28] as well as in Sonic Mega Collection Plus for PlayStation 2, Xbox, and Windows.[29]

Sonic the Hedgehog Genesis[edit]

A port titled Sonic the Hedgehog Genesis was released for the Game Boy Advance (GBA) on November 14, 2006 to mark the game's fifteenth anniversary. It included a few new features, such as the ability to save game progress, a level select option, and a special "Anniversary Mode" featuring the Spin Dash move that was not originally implemented until Sonic the Hedgehog 2. In addition, the view is slightly zoomed in and adapted for the GBA's widescreen aspect ratio.[30] The game received mostly negative reviews from critics,[31] mainly concerning its poor conversion to the Game Boy Advance, which resulted in a slow frame rate, chunky music, poor preservation of original gameplay, and numerous glitches.[32]

Compilation releases[edit]

Along with its sequels for the Genesis, Sonic the Hedgehog has been ported for a wide range of home consoles, handheld consoles, and personal computers.[33] It has appeared in compilations such as Sonic Compilation (1995) for the Genesis,[34] Sonic Jam (1997) for the Sega Saturn and,[35] Sonic Mega Collection (2002),[36] Sonic Mega Collection Plus (2004),[29] Sonic's Ultimate Genesis Collection (2009) for the Xbox 360 and PlayStation 3,[37] and Sonic Classic Collection (2010) for the Nintendo DS.[33]

Downloadable releases[edit]

Sonic the Hedgehog has been available for all three main seventh generation video game consoles. It was available on the Wii's Virtual Console service at its launch in 2006.[5] It was ported by Backbone Entertainment to the Xbox Live Arcade in 2007.[38] It has options for graphic smoothing, saving and loading current in-game progress, and resizing the gameplay window. It was later brought to the PlayStation Network in March 2011.

Additionally, Sonic the Hedgehog has been released downloadably on a number of other platforms. In 2007, the game was made available on the iTunes Store as a game for the iPod Nano with video, the iPod Classic, and iPod with video.[39] By 2008, Sonic the Hedgehog had sold 8 million paid downloads.[40] Sega made the first two games available for Apple's iOS in the spring of 2009.[41] The game was also present on GameTap.[42] In October 2010, Sonic the Hedgehog was downloadably released for Microsoft Windows,[43] which also got released to Steam.[44] In December 2012, it was released on the Google Play marketplace, as well as in the Amazon Appstore.[citation needed] A remastered mobile port, created using Christian Whitehead's Retro Engine previously used in the 2011 rerelease of Sonic CD, was released on iOS, replacing the original port, on May 15, 2013 with an Android version released the following day. The port features widescreen graphics, the ability to spin dash, a time attack mode and the unlockable option to play as Tails or Knuckles.[45][46] The game was renamed to 3D Sonic the Hedgehog and ported to the Nintendo 3DS in Japan on May 15, 2013, as part of its 3D Classics series. This version included a 3D mode and a Classic Screen mode that simulates the curve of a CRT screen.[47] The 3DS port was also released in PAL regions and North America in December 5, 2013.[48]


Aggregate scores
Aggregator Score
GameRankings 86.00%[49]
Review scores
Publication Score
Computer and Video Games 94%[9]
Dragon (magazine) 5/5 stars[50]
Electronic Gaming Monthly 9/10[51]
Eurogamer 9/10 (X360)[52]
GameSpot 7.3/10[53]
IGN 8/10 (Wii)[54]
Mean Machines 92%[55]

Sonic the Hedgehog received critical acclaim upon release and has continued to in retrospective reviews. It claims a score of 86.00% at the review aggregator GameRankings.[49] The game was seen instantly as a force that rivaled the Mario series,[9][50] particularly Super Mario World, which had recently been released for the Genesis' rival, the Super Nintendo Entertainment System. Paul Rand of Computer and Video Games compared the two in depth but declined to pick the better game, though he summarized that Sonic the Hedgehog was "faster, brighter and more colourful" while Super Mario World boasted more "depth of play".[9]

Reviewers applauded the game's graphics as colorful and detailed. Rand described the color scheme as "lively, but never garish" and praised the interaction of color with detail in the sprites, backgrounds, and animations. He also described the graphics as the best available for the Genesis.[9] Reviewer Boogie Man of GamePro called the graphics "eye-popping" and "gorgeous", especially the intricate backgrounds;[56] Mean Machines offered a similar opinion.[55] The Lessers (Hartley, Patricia, and Kirk) of Dragon said that "the graphics and animation in Sonic the Hedgehog make this a serious contender for the best video game of the year",[50] while GameZone called the animation "some of the smoothest and fastest ... ever seen".[57] The music and sound effects were also very well received; Dragon called them "great"[50] and GameZone "amazing".[57] Rand noted "stacks of catchy tunes and jingles" and called some of the sound effects "absolutely brilliant".[9] Mean Machines called the songs only "vaguely appealing" but was much more positive toward the sound effects.[55]

Critics also enjoyed the fast-paced gameplay, previously unheard of among platformers. Boogie Man was charmed by the "lightning-fast action",[56] while Electronic Gaming Monthly (EGM) exclaimed, "If you thought the Enterprise was quick, wait till you see Sonic at warp speed."[51] The game's difficulty was disputed, described as "impossible" by Rand[9] and only "average" by EGM.[51] Of the general enjoyment provided by the gameplay, Rand opined that it "plays like a dream",[9] GameZone predicted it would enchant players for hours,[57] and Boogie Man marveled at Sonic Team's ability to provide an engaging experience mostly from only running and jumping.[56] EGM, Dragon, and writer Paul from Mean Machines praised the level design, all singling out the presence of hidden rooms.[50][51][55] Paul did, however, find the event of losing all of one's rings to be frustrating.[55]

GameSpot has described the game as "one of the best platformers of all time", crediting it as a game that "revolutionized the platform genre and gave people a legitimate alternative to Nintendo's fat plumber [Mario]".[32] It received high praise from IGN as well, stating that it had stood the test of time, and "even after 16 years, the game still looks great. You'll be impressed by the clarity and color that come through [...] Few people realize how difficult it was to create Sonic's graphics engine, which allowed for the incredible rate of speed the game's known for. But the technical achievement impressed back in '91, and still does so today."[54] Mega placed the game at #3 in their Top Mega Drive Games of All Time.[58] Game Informer ranked it the 24th best game of all time in 2001. The staff associated Sega's success in the early 90's to this game.[59]

The game had sold over 15 million copies by February 2009.[60]


Effect on the industry[edit]

Sonic the Hedgehog greatly increased the popularity of the Sega Genesis in North America.[15] Bundling Sonic the Hedgehog with the Sega Genesis is credited with helping Sega gain 65% of the market share against Nintendo[clarification needed].[60] In large part due to the popularity of this game, the Genesis outsold the Super Nintendo in the United States nearly two to one during the 1991 holiday season. This success led to Sega overtaking Nintendo in January 1992 with control of 65% of the 16-bit console market, making it the first time Nintendo was not the console leader since December 1985.[61]

Sonic the Hedgehog added the element of momentum-based physics to the standard platform formula and introduced other unique elements as well, such as loops, springboards, high-speed devices, and rings, which are permanently associated with the series. While the speed contributed to the mix, the execution of the platforming element influenced the development of various 2D video games, including a subsequent wave of similar "mascot-based platforming games", such as Bubsy, Aero the Acrobat, Ristar, and Earthworm Jim.[15][62]

The game spawned numerous sequels. While the first games in the series were platform games, the series has expanded into other genres such as action-adventure, fighting, racing, role-playing, and sports. The franchise has also expanded into other media, including anime, cartoons, comic books, manga, and toys.[citation needed] The Sonic series has since become one of the best-selling video game franchises of all time.[63]

In other games[edit]

For the game's 10th anniversary, Sega included a 3D remake of the Green Hill Zone in the 2001 game Sonic Adventure 2.[citation needed] It was also featured as a battle arena in Sonic Battle. In 2008, the Green Hill Zone was included in the fighting game Super Smash Bros. Brawl as an unlockable stage.[citation needed] Sega Superstars Tennis features tennis courts that take place in Green Hill and Scrap Brain. For the game's 20th anniversary, Sega released Sonic Generations, which contains a remake of the Green Hill level. Additionally, the console versions of Sonic Generations feature the entire original Sonic the Hedgehog game as an unlockable reward, along with unlimited continues if the player runs out of lives.[64]


  1. ^ a b Thomason, Steve (January 2007). "Birth of a Hedgehog". Nintendo Power (Future Publishing) 20 (211): 72. 
  2. ^ Android | ケータイコンテンツ | SEGA
  3. ^ Dobson, Jason (June 23, 2006). "Sonic The Hedgehog Celebrates 15th Anniversary". Gamasutra. Retrieved September 23, 2014. 
  4. ^ Sonic the Hedgehog (MD / Mega Drive) News, Reviews, Trailer & Screenshots
  5. ^ a b c d e f g h Thomas, Lucas M. (January 26, 2007). "Sonic the Hedgehog VC Review". IGN. Retrieved February 23, 2014. 
  6. ^ a b c d Sonic Team (June 23, 1991). Sonic the Hedgehog. Sega. 
  7. ^ a b c Sonic the Hedgehog instruction manual, p. 10.
  8. ^ a b Mariott, Scott Alan. "Sonic the Hedgehog". Allgame. Retrieved February 6, 2014. 
  9. ^ a b c d e f g h i j Rand, Paul. "Give Me a Ring Sometime". Computer and Video Games (117): 18–21. 
  10. ^ Sonic the Hedgehog instruction manual, p. 2.
  11. ^ a b c Sonic the Hedgehog instruction manual, p. 6.
  12. ^ Sonic the Hedgehog instruction manual, p. 4.
  13. ^ Sonic the Hedgehog instruction manual, p. 7.
  14. ^ Sonic the Hedgehog instruction manual, pp. 4–5.
  15. ^ a b c d e f Kennedy, Sam. "Sonic Boom". Archived from the original on June 28, 2011. Retrieved September 24, 2014. 
  16. ^ a b c GI Staff (August 2003). "Sonic's Architect: GI Interviews Hirokazu Yasuhara". Game Informer 13 (124): 114–116. 
  17. ^ a b "The Making of... Sonic The Hedgehog". Edge (Bath: Future Publishing) (101): 118–121. September 2001. "...the Mega Drive allowed this stunning demonstration of rotation during the bonus stages. This was said to be impossible on the hardware at the time." 
  18. ^ a b Sega Video Game Illustrations. Nippon Shuppan Hanbai (Deutschland) GmbH. 1994. ISBN 3-910052-50-9. 
  19. ^ a b Kemps, Heidi (September 30, 2005). "Sega's Yuji Naka Talks!". GameSpy. Retrieved September 23, 2004. 
  20. ^ Sonic Team (November 4, 2010). Sonic Free Riders. Sega. "Vector: Whoa there! Hold on! Count us in for this race, too!" 
  22. ^ "[Update] Japanese Sonic 1&2 Soundtrack's Tracklist Revealed". ScrewAttack at Game Revolution[clarification needed]. February 11, 2011. Retrieved June 30, 2013. 
  23. ^ Earth Angel (March 1992). "Sega Master Pro Review: Sonic Boom". GamePro: 57–58. 
  24. ^ a b Thomas, Lucas M. (August 4, 2008). "Sonic the Hedgehog (Master System Version) Review". IGN. Retrieved September 21, 2014. 
  25. ^ Greening, Chris; Kotowski, Don (February 2011). "Interview with Yuzo Koshiro". Square Enix Music Online. Archived from the original on July 8, 2012. Retrieved September 12, 2014. 
  26. ^ McFerran, Damien. "Retroinspection: Master System". Retro Gamer (London, UK: Imagine Publishing) (44): 48–53. ISSN 1742-3155. 
  27. ^ "Search Result". Pan European Game Information. Retrieved September 21, 2014. 
  28. ^ Sonic Team (June 18, 2003). Sonic Adventure DX: Director's Cut. Sega. "Description: (SONIC THE HEDGEHOG) This is Sonic's first action game on GAME GEAR. Stop Dr. Eggman from getting his hands on the Chaos Emeralds! One Chaos Emerald is hidden in each zone. Collect them all to view the true ending." 
  29. ^ a b Goldstein, Hilary (November 3, 2004). "Sonic Mega Collection Plus: Step into the way-back machine to the days of 16-bit brilliance.". IGN. Retrieved September 21, 2014. 
  30. ^ Metts, Jonathan (June 23, 2006). "News Article: Sonic on GBA for 15th Anniversary". Nintendo World Report. Retrieved September 12, 2014. 
  31. ^ "Sonic the Hedgehog Genesis for Game Boy Advance Reviews". Metacritic. Retrieved September 12, 2014. 
  32. ^ a b Sonic the Hedgehog Genesis Review -
  33. ^ a b Harris, Craig (March 5, 2010). "Sonic Classic Collection Review". IGN. Retrieved September 23, 2014. 
  34. ^ Sonic Compilation instruction manual, p. 3.
  35. ^ Nutter, Lee (August 1997). "Review: Sonic Jam". Sega Saturn Magazine (EMAP): 68–69. 
  36. ^ Mirabella, Fran (November 12, 2002). "Sonic Mega Collection: A stellar compilation with plenty of trimmings.". IGN. Retrieved September 21, 2014. 
  37. ^ Miller, Greg (February 12, 2009). "Sonic's Ultimate Genesis Collection Review". IGN. Retrieved September 23, 2014. 
  38. ^ "Sonic the Hedgehog Arcade". IGN. IGN Entertainment, Inc. Retrieved 2013-06-09. 
  39. ^ Sonic the Hedgehog ipod details
  40. ^ Ben Parfitt (2008-05-29). "Sonic rings mobile success". Market for Home Computing and Video Games. Retrieved 2008-05-29. 
  41. ^ "CES 2009: ‘Sonic the Hedgehog’ and Other Sega Titles Coming to iPhone". GameCyte. 2009-01-07. Retrieved 2009-03-14. [unreliable source?]
  42. ^ "Sonic the Hedgehog - Play Now - GameTap". GameTap. Retrieved 2009-10-21. [unreliable source?]
  43. ^ "SEGA Genesis Classics: Series III on PC!". SEGA Blogs. Retrieved 2010-10-06. 
  44. ^ "Sonic the Hedgehog on Steam". Valve Corporation. 2013-10-26. Retrieved 2013-06-23. 
  45. ^ Bloom, Ryan. "REVIEW: 3D SONIC THE HEDGEHOG". Sonic United. Retrieved 2014-01-16. [unreliable source?]
  46. ^ "Sonic Wrecks – Sonic the Hedgehog 1 and 2 Remastered On The Way To iOS And Android". 2013-03-27. Retrieved 2013-06-29. [unreliable source?]
  47. ^ Reeves, Devin. "REVIEW: 3D Sonic the Hedgehog". Sonic United. Retrieved 2014-01-16. [unreliable source?]
  48. ^ Gil, Andrea. "Announced 3D Sonic the Hedgehog for Nintendo 3DS". TSSZ News. Retrieved 2013-06-29. [unreliable source?]
  49. ^ a b "Sonic the Hedgehog for Genesis". GameRankings. Retrieved February 6, 2014. 
  50. ^ a b c d e Lesser, Hartley; Lesser, Patricia & Lesser, Kirk (October 1991). "The Role of Computers". Dragon (174): 57–64. 
  51. ^ a b c d "Genesis – Sega / Sonic the Hedgehog". Electronic Gaming Monthly (24): 24. July 1991. 
  52. ^ Reed, Kristan (July 16, 2007). "Sonic the Hedgehog Review". Eurogamer. Retrieved February 9, 2012. 
  53. ^ Kasavin, Greg (November 19, 2006). "Sonic the Hedgehog Review". GameSpot. Retrieved September 10, 2014. 
  54. ^ a b Thomas, Lucas M. (January 26, 2007). "Sonic the Hedgehog VC Review". IGN. Retrieved February 6, 2014. 
  55. ^ a b c d e Leadbetter, Rich; Paul, Glancey (July 1991). "Mega Drive Review: Sonic the Hedgehog". Mean Machines (10): 42–44. Retrieved February 9, 2012. 
  56. ^ a b c Boogie Man (June 1991). "Genesis Pro Review: Hedgehog Heaven". GamePro: 42. 
  57. ^ a b c "Mega Drive: Sonic the Hedgehog". GameZone (1): 97. November 1991. 
  58. ^ Mega magazine issue 1, page 76, Future Publishing, Oct 1992
  59. ^ Cork, Jeff (November 16, 2009). "Game Informer's Top 100 Games Of All Time (Circa Issue 100)". Game Informer. Retrieved December 10, 2013. 
  60. ^ a b Sonic the Hedgehog GameTap Retrospective Pt. 3/4 (YouTube). GameTap (user gametap). February 16, 2009. Retrieved February 6, 2014. 
  61. ^ "This Month in Gaming History". Game Informer 12 (105): 117. January 2002. 
  62. ^ Hardcore Gaming 101: Earthworm Jim
  63. ^ Aamoth, Doug (November 15, 2012). "All-TIME 100 Video Games". Time. Retrieved September 2, 2014. 
  64. ^ SEGA Blog | Play Sonic 1 in X360 & PS3 Versions of Sonic Generations

External links[edit]