Sonic the Hedgehog (1991)

The story takes place on South Island, a location known for its abundance of ancient ruins and valuable gemstones. Among these treasures are the Chaos Emeralds, six powerful gems capable of providing energy to all living beings or fueling destructive weapons. However, acquiring these gems is a mystery because South Island is a constantly moving landmass, and the Emeralds are hidden within natural distortions on the island.^[18]Sonic the Hedgehog (Sega Mega Drive) Japanese instruction booklet, pgs. 11-12.

One day, the notorious Dr. Ivo Robotnik, a deranged human scientist, arrives on South Island with his minions, returning to his evil ways. He devises a wicked plan to defeat his arch-nemesis, Sonic the Hedgehog, using the power of science. Dr. Robotnik constructs a massive fortress called Scrap Brain on one corner of the island to develop his schemes. He also begins a relentless search for the Chaos Emeralds, vowing to unearth them even if it means excavating the entire island.^[19]Sonic the Hedgehog (Sega Mega Drive) Japanese instruction booklet, pgs. 13-14.

Upon hearing rumors of Dr. Robotnik’s ambitions, Sonic hurries to South Island to thwart the doctor’s plans. However, Sonic realizes that something is different compared to their previous encounters. He soon discovers that Dr. Robotnik has captured the local Animals and transformed them into mindless Badnik servants. Undeterred by his adversary’s taunts, Sonic embarks on a journey through the various Zones on South Island, freeing the Animals and defeating Dr. Robotnik and his contraptions along the way, all while searching for the Chaos Emeralds.

Eventually, Sonic infiltrates Scrap Brain and finds himself trapped inside. Dr. Robotnik activates a trap that causes the floor beneath Sonic to collapse, sending him into the ruins beneath the fortress. Determined, Sonic makes his way back into the stronghold and confronts his nemesis in a room filled with traps. Sonic destroys the room, leaving Dr. Robotnik defenseless. The mad scientist attempts to escape in his Egg Mobile, but Sonic delivers a final blow, causing the hovercraft to plummet.^[20](in Japanese) ソニックジャム　オフィシャルガイド. SoftBank. October 2, 1997. p. 30. ISBN 978-4797303377.

With Dr. Robotnik’s plans and Scrap Brain in ruins, peace is restored to South Island. The Badniks are destroyed, the Animals are freed from their captivity, and the island’s treasures are once again safe. Sonic returns to Green Hill, where he is greeted by the joyful local Animals celebrating his victory. The game’s ending varies depending on the player’s progress:

• If the player fails to collect all six Chaos Emeralds, Sonic will express annoyance at the player’s incomplete achievement but will still strike a pose while the text “SONIC THE HEDGEHOG” appears. Meanwhile, Dr. Robotnik will have obtained the Chaos Emeralds for himself. After the credits, a black screen shows Dr. Robotnik juggling any remaining Emeralds the player failed to collect, with the text “TRY AGAIN” displayed below him.
• If the player successfully collects all Chaos Emeralds, Sonic will race through Green Hill and release the Emeralds, causing the entire Zone to be filled with vibrant, blooming flowers. After a moment of surprise, Sonic jumps towards the screen, similar to the bad ending. Following the credits, an enraged Dr. Robotnik comically jumps on the text “END.”

Sonic the Hedgehog is a 2D side-scrolling platform game where the player controls Sonic as the only playable character. The objective is to complete a series of Acts in different Zones within a time limit of ten minutes. Each Act presents various enemies called “Badniks” and different terrains with obstacles and gimmicks. The level designs vary, offering unique layouts and gimmicks for each Zone. Along the way, the player can earn points by collecting items and defeating Badniks. To finish the first two Acts of a Zone, the player must reach a Goal Plate at the end. In most Zones, the final Act requires opening a Capsule after defeating a boss.

Sonic’s primary ability is running, which allows him to build momentum and reach high speeds, enabling him to navigate loops and ramps and perform high jumps. For offensive moves, Sonic can perform a rolling maneuver called the Super Sonic Spin Attack and a spinning jump known as the Super Sonic Spin Jump. These moves help Sonic destroy breakable objects and defeat enemies.

The game operates on a life system, and Sonic takes damage when touching Badniks, hazards, or bosses. Throughout the Acts, Rings are scattered, and Sonic can collect them by touching them. Rings provide an extra life after collecting 100 or 200 of them, grant points, and protect Sonic from damage. If Sonic takes damage, he will drop all his Rings, but some can be recollected before they disappear. If Sonic takes damage without any Rings, he loses a life. Sonic also loses a life if he stays underwater without replenishing his air supply, falls into a bottomless pit, gets crushed by a crusher, or runs out of time. Star Posts act as checkpoints, allowing the player to respawn at the last one touched after losing a life. If the player runs out of lives, the game ends. Item Boxes are scattered throughout each Act and contain power-ups that enhance Sonic’s abilities.

If the player has at least fifty Rings at the end of the first or second Act of a Zone, they can enter one of six Special Stages through a Giant Ring above the Goal Plate. Once all six Special Stages are cleared, the Giant Rings will no longer appear. If Sonic fails to jump into the Giant Ring before the Goal Plate stops spinning, he will run off the screen, preventing access to the Special Stage. At the end of each Act, the player can also find invisible Secret Bonuses by jumping during the score tallying.

In addition to the main objective, the player can collect the Chaos Emeralds by completing the Special Stages. Gathering all six Emeralds and completing the Final Zone unlocks the game’s good cinematic ending.

In the game, players can earn points through various actions and receive bonuses based on their performance. Here is a breakdown of the point system:

• Every 50,000 points: 1-Up (only in the Japanese version on Japanese Mega Drives)
• Hitting Badniks or breaking blocks:
  • First hit: 100 points
  • Second hit: 200 points
  • Third hit: 500 points
  • Fourth through fifteenth hit: 1,000 points each
  • Sixteenth hit and above: 10,000 points each
• Bumpers: Constantly award 10 points until the tenth hit
• Secret Bonus: Can give 100, 1,000, or 10,000 points each
• Defeating Dr. Eggman (boss): 1,000 points
• Special Stages:
  • Ring Bonus: 100 points per Ring collected
• End-of-Zone tally:
  • Ring Bonus: 100 points per Ring collected
• Time Bonus:
  • Less than 0:29: 50,000 points
  • 0:30 – 0:44: 10,000 points
  • 0:45 – 0:59: 5,000 points
  • 1:00 – 1:29: 4,000 points
  • 1:30 – 1:59: 3,000 points
  • 2:00 – 2:59: 2,000 points
  • 3:00 – 3:59: 1,000 points
  • 4:00 – 4:59: 500 points
  • More than 5:00: 0 points

Controls

Button formation	Movement
left/right	Walk/Run
up	Look up
down	Look down/Crouch
//	Super Sonic Spin Attack
left/right +  down	Super Sonic Spin Attack
START	Pause

Objects

Items

• Air bubble (first appearance)
• Chaos Emerald (first appearance)
• Giant Ring (first appearance)
• Item Box(first appearance)
  • 1-Up (first appearance)
  • Invincible (first appearance)
  • Power Sneakers (first appearance)
  • Shield (first appearance)
  • Super Ring (first appearance)
• Movable box (first appearance)
• Ring (first appearance)

Gimmicks and Obstacles

Playable characters

• Sonic the Hedgehog

Non-playable characters

• Dr. Ivo Robotnik
• Animals(first appearance)
  • Cucky (first appearance)
  • Flicky
  • Pecky (first appearance)
  • Picky (first appearance)
  • Pocky (first appearance)
  • Ricky (first appearance)
  • Rocky (first appearance)

Enemies

Green Hill Zone: This is the iconic starting Zone of the game, featuring lush green landscapes, loop-de-loops, and rolling hills. It sets the tone for the fast-paced and vibrant gameplay of Sonic the Hedgehog.

Marble Zone: In this Zone, Sonic explores ancient ruins filled with lava pits, crumbling platforms, and moving platforms. The player must navigate carefully to avoid hazards and defeat enemies.

Spring Yard Zone: This Zone takes place in a colorful cityscape filled with springs, bumpers, and pinball-like elements. Sonic can bounce around and gain momentum to reach higher areas.

Labyrinth Zone: This underwater Zone presents a challenging environment where Sonic must navigate through submerged tunnels, avoid drowning, and find air bubbles to replenish his oxygen supply.

Star Light Zone: This Zone features a futuristic cityscape with neon lights and high-speed sections. Sonic must navigate through platforms, avoid traps, and use his speed to overcome obstacles.

Scrap Brain Zone: This Zone serves as Dr. Robotnik’s fortress, filled with dangerous traps, moving platforms, and robotic enemies. Sonic must use his agility and timing to progress through this challenging Zone.

Final Zone: The final Zone is the climactic showdown against Dr. Robotnik. It consists of a single boss battle where Sonic must defeat Dr. Robotnik’s most powerful machine to save South Island and bring peace back to the land.

In the first five Zones of Sonic the Hedgehog, players have the chance to access a “Special Stage” by finishing the first or second Act with at least fifty Rings and finding a Giant Ring. Upon entering the Special Stage, Sonic falls through rotating mazes while continuously spinning. The goal is to guide Sonic through the maze and collect one of the six Chaos Emeralds hidden within.

During the Special Stage, players must avoid deceptive “Goal” obstacles that will eject them from the stage without obtaining the Chaos Emerald. Various gimmicks can either aid or hinder progress, such as Bumpers, Up and Down blocks that alter the rotating speed of the maze, or Reverse blocks that change the direction of rotation. Color Blocks that change color and vanish after being touched several times are also present. At the end of the Special Stage, a Chaos Emerald is encased in these Color Blocks, and successfully touching the Emerald marks the stage as completed.

There are ten chances to obtain Chaos Emeralds throughout the game, allowing players to fail up to four Special Stages if they aim to collect all six Emeralds before completing the game. While acquiring the gems is not essential to advance in the game, doing so is necessary for unlocking the good ending.

1. Egg Wrecker (Green Hill Zone)
2. Egg Scorcher (Marble Zone)
3. Egg Stinger (Spring Yard Zone)
4. Egg Mobile (Labyrinth Zone)
5. Egg Spiker (Star Light Zone)
6. Egg Crusher (Final Zone)

In the late 1980s, Sega faced limited success with their Sega Mega Drive arcade game ports, but they were determined to gain a stronger position in the market against their main competitor, Nintendo.^[22]Kennedy, Sam . Sonic Boom. 1Up.com. Archived from the original on June 4, 2011. Retrieved on September 24, 2014. In 1988, Sega of Japan initiated an in-house competition to create a character that could rival Nintendo’s Mario and be featured in a game that could sell over one million copies. This led to a dedicated effort from programmers and designers at Sega to develop a completely new character to compete with Mario^[23]“Sonic: A brief history“. MegaTech (No. 26): 24. January 20, 1994. Archived from the original. over the next three years.^[24]“Feature: When did you get yours?“. Mega (4): 16–20. December 1992. Archived from the original. Finally, in 1990, Sega tasked their in-house development studio with creating a game centered around a mascot for the company.^[25]Thomas, Lucas M. (January 20, 2007). Sonic the Hedgehog VC Review. IGN. Retrieved on February 23, 2014.^[26]“The Making of Sonic the Hedgehog”. Retro Gamer (Bournemouth: Imagine Publishing) (100): 46–49. February 2012. ISSN 1742-3155. Sega’s president, Hayao Nakayama, particularly desired a character as iconic as Mickey Mouse. Despite previously using Alex Kidd as their flagship mascot during the Sega Master System era, Alex Kidd was deemed unsuitable due to perceived similarities with Mario.

As the development process evolved at Sega, the team generated concepts for characters, game engines, and gameplay mechanics. They explored various ideas for the game’s protagonist, considering characters like a wolf, a bulldog, a robot, and a warrior. In 1989, Naoto Ohshima also conceived a game called “Twin Stars,” which revolved around two brothers protecting a dream world from the malevolent “Nightmare World,” governed by a villain named “Thirteen” due to the association of the number with misfortune. While this particular concept was eventually discarded, some elements, such as the smooth terrain, looping mechanics, and high-speed gameplay, were retained for further development.

Emphasizing the importance of speed, the team at Sega focused on fast creatures like kangaroos and squirrels, while dismissing ideas that did not align with the notion of swift characters. Among these concepts was a rabbit with prehensile ears capable of grabbing objects, which showed promise but proved too complex for the technical limitations of the Sega Genesis/Mega Drive hardware. Consequently, the team narrowed down their search to animals that could roll into a ball, as it aligned with their idea for an attack-based move. This led them to consider armadillos and hedgehogs as potential candidates.^[27]Sega Visions Interview with Yuji Naka (October 1992). Archived from the original on September 28, 2007. Retrieved on June 28, 2007. In the end, the hedgehog character, proposed by Naoto Ohshima, prevailed as the chosen protagonist. Interestingly, during Ohshima’s vacation in New York, he sought public opinions on his character sketches in Central Park, where Sonic received favorable feedback, while a character with a mustache, later known as Dr. Robotnik, ranked as the second-favorite among the locals.^[28]Sonic the Hedgehog’s origin story, according to the devs who made him. Game Developer (March 21, 2018). Archived from the original on February 1, 2022. Retrieved on February 22, 2022.

During the design phase of Sonic, the character was initially colored teal but later changed to a dark shade of blue to stand out against certain backgrounds^[29]Horowitz, Ken (December 5, 2006). Interview: Mark Cerny. Sega-16. Retrieved on October 12, 2014. “Mark Cerny: Sonic had been a lighter blue, but he was very hard to see against the ocean backgrounds, so his color was darkened at the last moment.” and match the color of the Sega logo. Naoto Ohshima, the character’s designer, combined Felix the Cat’s head with Mickey Mouse’s body^[30]Claiborn, Samuel (June 26, 2014). 21 Crazy Facts About Sonic and the Console War He Started. IGN. Retrieved on February 13, 2014. to create Sonic’s basic design. The inspiration for Sonic’s iconic shoes came from Michael Jackson’s boots on the album cover for “Bad” and the red and white color scheme of Santa Claus. Sonic’s personality was influenced by then-future U.S. President Bill Clinton’s “get it done” attitude, embodying a modern sensibility of addressing issues promptly instead of letting them linger.^[31]Sheffield, Brandon . Out of the Blue: Naoto Ohshima Speaks. Gamasutra. Retrieved on December 13, 2009.^[32]Yahoo Playback . Yahoo Playback #94. Yahoo!. Archived from the original on December 15, 2009. Retrieved on December 13, 2009.^[33]Ashcraft, Brian . Sonic’s Shoes Inspired by Michael Jackson. Kotaku. Retrieved on December 15, 2009. Yuji Naka, the programmer, wanted Sonic’s blue color to symbolize peace, trust, and coolness, which reflect the attributes of Sonic’s character. Sonic’s spikes were emphasized to make him appear sleeker, and the decision to allow him to spin while jumping enabled both attacking and jumping to be controlled with a single button press.^[34]Ponce, Tony (February 27, 2013). Review: The History of Sonic The Hedgehog. Destructoid. Retrieved on October 11, 2014. Originally named “Mr. Hedgehog,”^[35] Yuji Naka on Twitter (Japanese). Twitter (January 24, 2021). Archived from the original on January 24, 2021. “悔しいのでもう一度挑戦しましたがもっと判らなかった感じです。「セガの看板キャラクターであるソニック。世に出る前に彼に付けられていた名前を選べ」と言う問題が判りませんでした。作った人なのにね。セガい共通テスト受験終了！” the eight-member team^[36]“Interview with Yuji Naka: The Creator of Sonic The Hedgehog”. Sega Visions 3, no. 9: 20. August–September 1992. later changed his name to “Sonic” to represent speed.^[37] Naoto Ohshima (2013). “The History Of Sonic The Hedgehog”. in Les Editions Pix’n Love (ed.)]. Interview With Naoto Ôshima. UDON Entertainment Corp. pp. 96–101. ISBN 978-1-926778-96-9.

Various ideas were proposed to develop Sonic’s character further, including placing him in a rock band, giving him fangs, and providing him with a human girlfriend named Madonna.^[38]Loveridge, Sam (June 23, 2016). 14 things you didn’t know about Sonic the Hedgehog. Digital Spy. Retrieved on June 10, 2017. However, Sega of America decided to keep his identity simple and scrapped these ideas. Initially, Sega of America had concerns that most Americans would not be familiar with hedgehogs, leading to suggestions for a complete redesign. Yet, after negotiations with Sonic Team, only minor design changes were made.

To bring their protagonist to life, Sega enlisted the talented programmer Yuji Naka, who had impressed them with his previous work. Interestingly, Naka, a fan of Super Mario Bros., aimed to create a game with faster gameplay than Mario’s.^[39]“Sonic Boom: The Success Story Of Sonic The Hedgehog”. Retro Gamer Sega Archives^[40]Yuji Naka (2014). Yuji Naka Game Designer. Read-Only Memory. pp. 278-279. ISBN 978-0-9575768-1-0. The team, consisting of two programmers, two sound engineers, and three designers,^[41]Yuji Naka (2013). “The History Of Sonic The Hedgehog”. in Les Editions Pix’n Love (ed.). Interview With Yuji Naka. UDON Entertainment Corp. pp. 90–95. ISBN 978-1-926778-96-9. began working on the project, which initially had the code name “Defeat Mario.” However, they faced challenges, including difficulties with Ohshima’s initial rabbit character, leading to the decision to make Sonic playable with only one button. With Hirokazu Yasuhara’s assistance as lead designer, they introduced Sonic rolling into a ball as part of his moveset.

Due to Mario’s popularity, Naka wanted Sonic to compete in the American market. However, during testing, they faced animation and speed-related issues. To maintain fluidity, Naka developed an algorithm. Despite disagreements about the game’s speed, the team eventually decided to slow it down.^[42]Les Editions Pix’n Love, ed (2013). “Zone 1 Genesis”. The History Of Sonic the Hedgehog. Ontario: UDON Entertainment Corp. pp. 20–33. ISBN 978-1-926778-96-9. The gameplay originated from Naka’s tech demo, allowing a fast-moving character to roll in a ball through a winding tube. Yasuhara’s designs for levels aimed to cater to both hardcore and casual gamers.^[43]GI Staff (August 2003). “Sonic’s Architect: GI Interviews Hirokazu Yasuhara”. Game Informer (124): 114–116. The team worked tirelessly for several months, undergoing extensive testing and redesigning to showcase the Sega Mega Drive’s capabilities.

While the team initially planned a two-player mode, it wasn’t implemented due to programming limitations, but it was eventually featured in Sonic the Hedgehog 2. The idea of a Sound Test featuring Sonic breakdancing with a band of animal characters was abandoned due to time constraints, and the memorable “Se-ga!” chant was added instead.^[44]Kemps, Heidi (September 30, 2005). Sega’s Yuji Naka Talks!. Gamespy. Retrieved on September 23, 2004.

During this time, Yuji Naka’s relationship with Sega became strained, and he received little recognition for his work. After the game’s release, he eventually left the company, although Sega of America later hired him. Before his departure, Naka decided to rebel against Sega’s policy of not crediting developers by secretly inserting a few names in black text on a black background, visible only by inspecting the game’s code.

Naka faced significant challenges in level design, particularly in creating wide maps that wouldn’t confuse players. The development of Green Hill Zone, one of the game’s iconic stages, took around eight months and went through multiple restarts. Despite the difficulties, Naka found the process intriguing. The team aimed to create smooth maps, but the high speed of the game posed challenges, such as Sonic breaking through loop structures instead of running around them, creating the illusion of moving backward.

Hirokazu Yasuhara, the lead designer, wanted to ensure the game appealed to both Japanese and American players, leading to multiple redesigns of Green Hill Zone. The checkered ground in the level was inspired by 3D image rendering from computers, influenced by the work of Sega developer Yu Suzuki in Space Harrier. To stay informed about their competitors, the team read Famitsu magazines to avoid making similar mistakes.

When it came to the packaging and release, Akira Watanabe, the game-package illustrator, aimed to make the characters colorful and distinct. Sega requested a package design that resembled pop art, resulting in an original and stylish packaging.^[45]Sega Video Game Illustrations. Nippon Shuppan Hanbai (Deutschland) GmbH. 1994. ISBN 3-910052-50-9. Sega strategically revealed Sonic the Hedgehog at the January 1991 International Consumer Electronics Show, where it garnered significant attention and won the CES award for innovation.^[46]Les Editions Pix’n Love, ed (2013). “Zone 2 A New Face In The Magazines”. The History Of Sonic the Hedgehog. Ontario: UDON Entertainment Corp. pp. 34–41. ISBN 978-1-926778-96-9.

Sega of America’s CEO, Tom Kalinske, wanted assurance of Sonic’s success, leading to play-testing across the United States. After a comparison with Mario, 80 percent of participants preferred Sonic the Hedgehog. The game was then showcased at the 1991 Summer Consumer Electronics Show.^[47]Stuart, Keith (2014). “The Blue Blur”. in Wall, Darren]. Sega Mega Drive/Genesis Collected Works. Read-Only Memory. pp. 20–24. ISBN 978-0-9575768-1-0. Subsequently, Sonic the Hedgehog was released in North America on June 23, 1991,^[48]“The Making of … Sonic The Hedgehog”. Edge (Future Publishing) (101): 118–121. September 2001. ISSN 1350-1593. “Sonic was delivering [the kind of] high speed no other [game] was capable of, and 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.” followed by releases in PAL regions and Japan the next month.^[49]Leadbetter, Rich; Glancey, Paul (July 1991). “Mega Drive Review: Sonic the Hedgehog“. Mean Machines (10): 42–44. ISSN 0960-4952. Archived from the original on March 5, 2016.. Retrieved on February 9, 2012.^[50][セガハード大百科] メガドライブ対応ソフトウェア（セガ発売 (Japanese). Sega. Archived from the original on November 24, 2012. Retrieved on December 18, 2015. Later, in November 1991, Sega of America bundled the game with American Genesis consoles,^[51]Lynch, Dennis (November 29, 1991). Super NES, Sega Genesis in 16-bit duel. Chicago Tribune. Retrieved on September 8, 2021.^[52]“Games for Grown-Ups: Speedy sprites“. Popular Mechanics (Hearst Magazines) (168): 76. December 1991. Archived from the original. Retrieved on January 3, 2017. effectively boosting sales of Sega Genesis/Mega Drive units. As part of their marketing strategy, Sega of America established Sonic as their new mascot.

Sega director Fujio Minegishi had connections in the music industry and suggested his friend Yūzō Kayama to compose the Sonic score. However, Sonic Team felt that Kayama’s music wouldn’t be the right fit for the game, so they instead approached Masato Nakamura, the bassist and songwriter of the J-pop band Dreams Come True.^[53] “ソニックチーム物語” (in Japanese). Sega Magazine (SoftBank Creative): 9–13. January 1997. Archived from the original on December 17, 2019. Nakamura was surprised by the offer as he had just started with Dreams Come True, but he accepted the opportunity because he was inspired by the team’s determination to outperform Nintendo. Working with limited resources, particularly only being able to play four sounds concurrently, was a challenge for Nakamura, especially since he lacked experience in computer-based music. Nevertheless, he composed the soundtrack simultaneously with Dreams Come True’s album Million Kisses,^[54] Sega of America . Interview with Masato Nakamura. Sonic Central. Sega. Archived from the original on December 23, 2008. showcasing his dedication and talent.

Nakamura’s compositions for the game became iconic and played a significant role in defining the Sonic series’ musical identity. The main theme of Sonic the Hedgehog, which played on the title screen, became particularly famous and was later reused in various subsequent Sonic games, becoming a hallmark of the franchise. Another popular track was the theme for Green Hill Zone, which also saw reuse and remixing in several other games of the series.

Over twenty years after the original release of Sonic the Hedgehog, a three-disc compilation of music from both Sonic the Hedgehog and Sonic the Hedgehog 2 was released in Japan under the title “Sonic the Hedgehog 1&2 Soundtrack” on October 19, 2011. The album featured original tracks from both games on the first disc, Nakamura’s demo recordings before programming them into the Sega Mega Drive on the second disc, and songs by Dreams Come True and their associated Akon remixes on the third disc.^[55]中村正人 from DREAMS COME TRUE / ソニック・ザ・ヘッジホッグ1&2 サウンドトラック【CD】 (Japanese). Universal Music Japan. Retrieved on February 20, 2015. This compilation allowed fans to revisit and appreciate the timeless music that accompanied the iconic game.

These are the achievements which add to the player’s Gamerscore on the Xbox Live Arcade and PlayStation Network versions of Sonic the Hedgehog.

Icon	Name	Requirements	Trophy Class	Gamescore
	Clear Green	Clear Green Hill Zone.		5
	Star Light Zone	Get to Star Light Zone.		5
	Spring Yard Zone	Get to Spring Yard Zone.		7
	Labyrinth Zone	Get to Labyrinth Zone.		8
	Fast Green	Beat Green Hill Zone Act 1 in under 35 seconds.		10
	Chaos Emerald	Get one Chaos Emerald.		10
	Centurion	Get 100 or more Rings.		10
	Fast Marble	Beat Marble Zone Act 1 in under 80 seconds.		15
	Win	Beat the game.		25
	Fast Win	Beat the game in under 40 minutes.		30
	Chaos Master	Get all the Chaos Emeralds.		35
	Perfect Win	Beat the game without dying.		40

Sega supported the “Wonder 3” tour of Dreams Come True by featuring Sonic imagery on the tour bus, promoting the game through pamphlets, and showcasing game footage above the stage before its official release.^[56]Masato Nakamura interview (Flash). Sonic Central. Sega. Archived from the original on December 23, 2008. Retrieved on February 7, 2006.

• Level Select: At the title screen, press  ↑ ↓ ← → then hold  and press Start.^{[note 1]}Does not work on the Xbox Live Arcade or PlayStation Network version of the game, nor in the unlockable mini-game in the Xbox 360 version of Sonic Generations.
• Debug Mode: At the title screen, press  ↑  ↓  ←  →  (or   ↑ ↓ ← →) Start then hold  until the game starts.

Several spin-off series for the Sonic the Hedgehog franchise have featured numerous adaptations and references to the original game.

In the Sonic the Comic series published by Fleetway Editions, it was suggested that the events of the game occurred within its storyline. While there was no direct adaptation, the game’s events were referenced in Sonic the Comic #26, titled “Kintobor spelled backwards is…”.

The Sonic X comic series, published by Archie Comics, later created an adaptation of Sonic the Hedgehog in issues #10-#11 as part of the “No Thanks for the Memories!” storyline. However, this adaptation took place in a virtual world, deviating from the original game’s storyline. Archie Comics also made another adaptation of Sonic the Hedgehog in their “Genesis” arc, covered in Sonic the Hedgehog #226-#227. It was also stated that the game’s events took place within the post-Super Genesis Wave timeline. An adaptation of these events in that timeline was depicted in Sonic the Hedgehog #288, serving as the first part of the “Genesis of a Hero” storyline.

• The game has two versions, with the revised edition being more prevalent in Japan, but it was also released globally in smaller quantities. This update includes slight changes to the game’s programming and introduces some visual enhancements like scrolling clouds in Green Hill Zone and water ripples in Labyrinth Zone. It also fixes the Zone order on the Level Select. The later version of the game is used for most re-releases, and the scrolling clouds in Green Hill Zone persist in subsequent appearances of the level.
• Sonic the Hedgehog initially featured only six Chaos Emeralds, and the seventh (turquoise) emerald was introduced in the sequel, which meant that the super transformation was not available in the original release. However, in the Android re-release ports of the game, this seventh emerald was added, enabling Sonic to transform into Super Sonic.
• Rui Sousa holds the world high score record for Sonic the Hedgehog with a score of 1,559,180, achieved on March 21, 2015.^[67]Highest Score In “Sonic The Hedgehog” With Five-Life Limit (Sega Genesis). Record Setter (March 21, 2015).
• Interestingly, the PlayStation Network port of the game was initially rated E10+ by the ESRB, but it was later changed to an E rating in 2013.
• In the G4 special Top 100 Video Games of All Time, the game was ranked at #50.^[68]#50 Sonic the Hedgehog (Top 100 Video Games of All Time). YouTube (May 21, 2013).
• Sonic the Hedgehog was listed in the book 1001 Video Games You Must Play Before You Die, along with Sonic the Hedgehog 2 and Sonic Adventure.^[69]AdamBC13 (February 21, 2011). 1001 Video Games You Must Play Before You Die. Archived from the original on February 23, 2011.
• The release date of the game, June 23, is also considered the canonical birthday of Sonic the Hedgehog.
• In the European manual of Sonic the Hedgehog, there was an error in the Spanish and Italian translations, which mistakenly referred to Sonic as a porcupine.
• This game holds the record for the most ports and re-releases among all Sonic games, with more than a dozen versions available.