Sonic the Hedgehog

Sonic the Hedgehog (ソニック・ザ・ヘッジホッグ) is a Japanese video game series and media franchise created by Sonic Team and owned by Sega. The franchise centers on Sonic, an anthropomorphic blue hedgehog who battles the evil Doctor Eggman, a mad scientist. The main Sonic the Hedgehog games are platformers developed by Sonic Team; other games, developed by various studios, include spin-offs set in the racing, fighting, party and sports genres. The franchise also incorporates printed media, animations, a 2020 feature film, and merchandise.

The first Sonic game, released in 1991 for the Sega Genesis, was developed after Sega requested a new mascot character to replace Alex Kidd and compete with Nintendo's mascot Mario. Its success helped Sega become one of the leading video game companies during the 16-bit era of the early 1990s. Sega Technical Institute developed the next three Sonic games in addition to Sonic Spinball (1993). The first major 3D Sonic game, Sonic Adventure, was released in 1998 for the Dreamcast. After Sega exited the console market and shifted to third-party development in 2001, the series continued on Nintendo, Xbox, and PlayStation systems.

While Sonic games typically feature unique game mechanics and stories, they are linked by several recurring elements, such as the health system, locations, and momentum and speed-based gameplay. Each game typically features Sonic setting out on a quest to stop Eggman's schemes for world domination. Gameplay involves running at high speeds through levels that include springs, slopes, bottomless pits, and vertical loops. While Sonic and Eggman were the only characters introduced in the first game, the series would go on to have a large cast of characters; some, such as Miles "Tails" Prower, Knuckles the Echidna, and Shadow the Hedgehog, starred in self-titled spin-offs.

Sonic the Hedgehog is Sega's flagship franchise and one of the bestselling video game franchises, selling over 89million by March 2011 and grossing over US$5 billion by 2014. The sum of series sales and free-to-play mobile game downloads totaled over 800million by 2018. Several Sonic games appear on lists of the greatest games of all time, and the series has influenced internet and popular culture, as well as games featuring animal mascots. However, Sonic games have also been criticized for a perceived decline in quality over the years.

Conception and Genesis games (1991—1995)
In 1990, Sega of Japan president Hayao Nakayama decided Sega needed a flagship series and mascot to compete with Nintendo's Mario series. Nintendo had recently released Super Mario Bros. 3, at the time the bestselling video game ever. Sega's strategy had been based on its earlier release of the Sega Genesis in the 16-bit era and its reliance on its successful arcade business to port games to the console. However, Nakayama recognized that Sega needed a star character in a game that could demonstrate the power of the hardware of the Sega Genesis. Sega's mascot, Alex Kidd, was considered too similar to Mario. Several character designs were submitted as part of a contest; the winning character was a teal hedgehog created by artist Naoto Ohshima. The gameplay of Sonic the Hedgehog originated with 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, a concept fleshed out with Ohshima's character design and levels conceived by designer Hirokazu Yasuhara.

Sonic's color was chosen to match Sega's cobalt blue logo, and his shoes evolved from a design inspired by Michael Jackson's boots; the red shoe color was inspired by Santa Claus and the cover of Jackson's 1987 album Bad. His personality was based on Bill Clinton's "can-do" attitude. The antagonist, Doctor Eggman, was another character Ohshima had designed for the contest. The development team thought the rejected design was excellent and retooled the character into a villain. The team took the name Sonic Team for the game's release. Although Sega of America CEO Michael Katz and Sega of America's marketing experts were certain that Sonic would not catch on with American children, Katz's replacement, Tom Kalinske, arranged to place Sonic the Hedgehog as the pack-in game with the Genesis. Featuring speedy gameplay, Sonic the Hedgehog greatly increased the popularity of the Sega Genesis in North America and is credited with helping Sega gain 65% of the market share against Nintendo.



Naka was dissatisfied with his treatment at Sega and felt he received little credit for his involvement in the success. He quit but was hired by Mark Cerny to work at the US-based Sega Technical Institute (STI), with a higher salary and more creative freedom. Yashura also decided to move to STI. STI began work on Sonic the Hedgehog 2 in November 1991. Level artist Yasushi Yamaguchi designed Sonic's new sidekick, Tails, a two-tailed fox that can fly and was inspired by Japanese folklore about the kitsune. While STI made Sonic 2, Ohshima led a team in Japan to create Sonic CD for the Sega CD. Like its predecessor, Sonic the Hedgehog 2 was a major success, but its development suffered from the language barrier and cultural differences between the Japanese and American developers.

Once development on Sonic 2 concluded, Cerny departed and was replaced by Roger Hector. Under Hector, STI was divided into two teams: the Japanese developers led by Naka, and the American developers. The Japanese began to work on Sonic the Hedgehog 3 and Sonic & Knuckles. The two were intended to be one large game, but time was limited and the manufacturing costs of a 34-megabit cartridge with NVRAM were prohibitively expensive. The team split the game in half, giving the developers more time to finish the second part, and splitting the cost between two cartridges. The games introduced Sonic's rival Knuckles, created by artist Takashi Thomas Yuda. When Sega management realized Sonic the Hedgehog 3 would not be completed in time for the 1993 holiday shopping season, it commissioned the American team to make a new game, the spin-off Sonic Spinball. Following the release of Sonic & Knuckles in 1994, Yasuhara quit Sega and Naka returned to Japan, having been offered a role as a producer. He was reunited with Ohshima and brought with him Takashi Iizuka, who had worked with Naka's team at STI.

A number of Sonic games were developed for Sega's 8-bit consoles, the Master System and Game Gear. The first, an 8-bit version of the first game, was developed by Ancient to promote the handheld Game Gear and was released in December 1991. Aspect Co. developed most of the subsequent 8-bit Sonic games, beginning with a version of Sonic 2. Other notable Sonic games released during this period include Dr. Robotnik's Mean Bean Machine (a Western localization of the Japanese puzzle game Puyo Puyo), SegaSonic the Hedgehog (an arcade game), and Knuckles' Chaotix (a spin-off for the Genesis's 32X add-on starring Knuckles).

Saturn (1996—1998)


During the development of Sonic 3, the developers had created a prototype for an isometric Sonic game. Sega reused this concept for Sonic 3D Blast (1996), commissioned towards the end of the Genesis's lifecycle. In Japan, Sonic Team was preoccupied with new intellectual property, Nights into Dreams (1996), for Sega's 32-bit Saturn console, so development of 3D Blast was outsourced to the British studio Traveller's Tales. While 3D Blast sold well, it was criticized for its gameplay, controls, and slow pace. Meanwhile, in America, STI worked on Sonic X-treme, a 3D Sonic game for the Saturn intended for the 1996 holiday shopping season. X-treme 's development was hindered by disputes between Sega of America and Japan, Naka's refusal to let STI use the Nights into Dreams game engine, and problems adapting the series to 3D. After two of the lead developers became ill, the game was canceled.

With X-treme cancellation, Sega ported 3D Blast to the console with updated graphics and bonus levels developed by Sonic Team. In 1997, Sega announced "Project Sonic", a promotional campaign aimed at increasing market awareness of and renewing excitement for the Sonic brand. The first Project Sonic release, the compilation Sonic Jam, included a 3D overworld used by Sonic Team to experiment with 3D Sonic gameplay. Sonic Team and Traveller's Tales collaborated again to produce the second Project Sonic game—Sonic R, a 3D racing game and the only original Sonic game for the Saturn. The cancellation of Sonic X-treme, as well as the Saturn's general lack of Sonic games, are considered important factors in the Saturn's struggle to find an audience. The series' popularity diminished; according to Nick Thorpe of Retro Gamer, "[b]y mid-1997 Sonic had essentially been shuffled into the background... it was astonishing to see that just six years after his debut, Sonic was already retro."

Jump to 3D (1998—2005)
With its Sonic Jam experiments, Sonic Team began developing a 3D Sonic platformer for the Saturn. The project stemmed from a proposal by Iizuka to develop a Sonic role-playing video game (RPG) with an emphasis on storytelling. The Saturn's limited capabilities made development difficult, so Sonic Team transitioned development to the Dreamcast, which Naka believed would allow for the ultimate Sonic game. Sonic Adventure, released in 1998, was one of the largest video games ever created at the time, and introduced elements that became series staples. Artist Yuji Uekawa redesigned the characters to better suit 3D, with a style influenced by comics and animation. Sonic Team's American division, Sonic Team USA, developed a sequel, Sonic Adventure 2 (2001), designed to be more action-oriented. While both Adventure games were well-received and the first sold over two million copies, consumer interest in the Dreamcast quickly faded, and Sega's attempts to spur sales through lower prices and cash rebates caused escalating financial losses.

In January 2001, Sega announced it was discontinuing the Dreamcast to become a third-party developer. Afterward, Sega released an expanded port of Sonic Adventure 2 for the Nintendo GameCube, chosen for its 56k technology. Sonic Team USA also began developing the first multi-platform Sonic game, Sonic Heroes (2003), for the GameCube, Microsoft's Xbox, and Sony's PlayStation 2. The game was designed for a broad audience, and Sonic Team revived elements, such as special stages and the Chaotix characters, not seen since the Genesis era. Reviews for Sonic Heroes were mixed; while its graphics and gameplay were praised, critics felt it failed to address the problems of previous Sonic games, such as the camera. After completing Sonic Heroes, Sonic Team USA was renamed Sega Studios USA. Its next project was Shadow the Hedgehog (2005), a Sonic spin-off starring Shadow, a character introduced in Adventure 2. While Shadow retains most elements from previous Sonic games, it was aimed at a mature audience and introduces third-person shooting and nonlinear gameplay. Shadow the Hedgehog was critically panned for its mature themes and level design, but was a commercial success, selling at least 1.59 million units.

Sega continued to release 2D Sonic games. In 1999, it collaborated with SNK to produce Sonic the Hedgehog Pocket Adventure, an adaptation of Sonic 2 for the Neo Geo Pocket Color. Some SNK staff went on to form Dimps the following year and developed original 2D Sonic games—Sonic Advance (2001), Sonic Advance 2 (2002), and Sonic Advance 3 (2004)—for Nintendo's Game Boy Advance (GBA). Sonic Advance was outsourced to Dimps because Sonic Team was understaffed with employees familiar with the GBA's hardware. Dimps also developed Sonic Rush (2005) for the Nintendo DS, which uses a 2.5D perspective. Further spin-offs included the party game Sonic Shuffle (2000), the pinball game Sonic Pinball Party (2003), and the fighting game Sonic Battle (2003).

Seventh-generation consoles (2006—2012)
For the franchise's 15th anniversary in 2006, Sonic Team developed Sonic Riders, Sonic the Hedgehog, and a GBA port of the original Sonic. Sonic Riders, the first Sonic racing game since Sonic R, was designed to appeal to Sonic and extreme sports fans. With a more realistic setting than previous entries, Sonic the Hedgehog was intended to reboot the series for seventh generation consoles such as the Xbox 360 and PlayStation 3. The game faced serious development problems; Naka resigned as head of Sonic Team to form Prope and stringent deadlines rushed development. None of the 15th-anniversary Sonic games were successful critically, and Sonic the Hedgehog in particular was panned. Production on the next major Sonic game, Sonic Unleashed (2008), began in 2005. It was conceived as a sequel to Adventure 2, but became a standalone entry after Sonic Team introduced innovations to separate it from the Adventure games. With Unleashed, Sonic Team sought to combine the best aspects of 2D and 3D Sonic games and address criticisms of previous 3D entries, although reviews were mixed.

The first Sonic game for the Nintendo Wii, Sonic and the Secret Rings (2007), takes place in the world of Arabian Nights and was released instead of a port of the 2006 Sonic the Hedgehog. Citing lengthy development times, Sega switched plans and conceived a game that would use the motion detection of the Wii Remote. Sega released a sequel, Sonic and the Black Knight, set in the world of King Arthur, in 2009. A Sonic Riders sequel, Zero Gravity (2008), and a version of Unleashed were also developed for the Wii and PlayStation 2. Sega collaborated with former rival Nintendo to produce Mario & Sonic, an Olympic Games-themed crossover with the Mario franchise. The first Mario & Sonic game was released in 2007 to tie in with the 2008 Summer Olympics, and sequels based on the 2010 Winter Olympics and the 2012 Summer Olympics were released in 2009 and 2011. Dimps returned to the Sonic series with Sonic Rush Adventure, a sequel to Sonic Rush, in 2007. DS versions of the Mario & Sonic games were produced, while BioWare developed the first Sonic RPG, Sonic Chronicles: The Dark Brotherhood (2008), also for the DS.

Following a string of poorly received Sonic games, Sonic Team refocused on speed and more traditional side-scrolling. Sonic the Hedgehog 4, a side-scrolling episodic sequel to Sonic & Knuckles co-developed by Sonic Team and Dimps, began with Episode I in 2010, followed by Episode II in 2012. Later in 2010, Sega released Sonic Colors for the Wii and DS, expanding on the well received aspects of Unleashed and introduced the Wisp power-ups. For the series' 20th anniversary in 2011, Sega released Sonic Generations for the Xbox 360, PlayStation 3, and Windows; a separate version was developed by Dimps for the Nintendo 3DS. Sonic Generations featured remakes of levels from previous Sonic games and reintroduced the "classic" Sonic design from the Genesis era. These efforts were better received, especially in comparison to the 2006 game and Unleashed. The British studio Sumo Digital developed Sonic & Sega All-Stars Racing (2010) and Sonic & All-Stars Racing Transformed (2012), crossover kart racing games featuring Sonic and other Sega franchises.

Eighth-generation consoles (2013–present)
In May 2013, Nintendo announced it was collaborating with Sega to produce three Sonic games for its Wii U and 3DS platforms. The first game in the partnership, 2013's Sonic Lost World, was also the first Sonic game for eighth generation hardware. Sonic Lost World was designed to be streamlined and fluid in movement and design, borrowing elements from Nintendo's Super Mario Galaxy games and the canceled X-treme. The second was Mario & Sonic at the Sochi 2014 Olympic Winter Games (2013) for the Wii U, the fourth Mario & Sonic game and a 2014 Winter Olympics tie-in. The deal was completed in 2014 with the release of Sonic Boom: Rise of Lyric for the Wii U and Sonic Boom: Shattered Crystal for the 3DS; these games were based on the Sonic Boom television series (see Animation section). None of the games were well-received; Sonic Lost World polarized critics, while Mario & Sonic at the Sochi 2014 Olympic Winter Games received mediocre reviews and the Sonic Boom games were panned. Nonetheless, the fifth Mario & Sonic game, Mario & Sonic at the Rio 2016 Olympic Games, and Sonic Boom: Fire & Ice, a Shattered Crystal sequel, were released in 2016.

Sega began to release more Sonic games for mobile phones, such as iOS and Android devices. After he developed a version of Sonic CD for modern consoles in 2011, Australian programmer Christian "Taxman" Whitehead collaborated with fellow Sonic fandom member Simon "Stealth" Thomley to develop remasters of the original Sonic the Hedgehog and Sonic the Hedgehog 2 for iOS and Android, which were released in 2013. The remasters were developed using Whitehead's Retro Engine, an engine tailored for 2D projects, and their upgrades received considerable praise. Sonic Dash (2013), a Temple Run-style endless runner, was developed by Hardlight and was downloaded over 100 million times by 2015, and received a Sonic Boom-themed sequel that year. Sonic Team released Sonic Runners, its first game for mobile devices, in 2015. Sonic Runners was also an endless runner, but was unsuccessful and discontinued a year after release. Gameloft released a sequel, Sonic Runners Adventure, in 2017 to generally positive reviews.

At the San Diego Comic-Con in July 2016, Sega announced two Sonic games to coincide with the series' 25th anniversary: Sonic Mania and Sonic Forces. Both were released for the PlayStation 4, Xbox One, Nintendo Switch, and Windows in 2017. Sonic Mania was developed by the independent game developers PagodaWest Games and Headcannon with a staff comprising members of the Sonic fandom; Whitehead conceived the project and served as director. The game, which emulates the gameplay and visuals of the Genesis entries, was hailed as a return to form for the franchise. Meanwhile, Sonic Team developed Sonic Forces, which revives the dual gameplay of Sonic Generations along with a third gameplay style featuring the player's custom character. Sonic Forces received mixed reviews, with criticism directed at its short length. At SXSW in March 2019, Iizuka confirmed a new mainline Sonic game was in development, although he did not specify any details. Additionally, Sumo Digital developed another Sonic kart racing game, Team Sonic Racing (2019). Unlike its predecessors, Team Sonic Racing only features Sonic characters, as Sumo Digital wanted to expand the series' world and character roster.

Characters
The Sonic series has a great many characters; the most frequently appearing are titular protagonist Sonic the Hedgehog, a blue hedgehog able to run at supersonic speeds, and recurring villain Dr. Eggman, an evil scientist whose ambition is to conquer the world. Among Sonic's many allies, the most well-known include: Miles "Tails" Prower, a twin-tailed, highly intelligent yellow fox who is Sonic's sidekick and best friend; Amy Rose, a pink hedgehog who is Sonic's self-proclaimed girlfriend and a hero in her own right; Knuckles the Echidna, a coolheaded red echidna who is the guardian of the Master Emerald; Shadow the Hedgehog, an anti-heroic doppelgänger of Sonic with a dark past; and Metal Sonic, a robotic clone of Sonic, built by Doctor Eggman with a sole purpose of destroying Sonic.

Rings
One distinctive feature of Sonic games are collectible golden rings spread throughout the levels. This gameplay device allows players possessing at least one ring to survive upon sustaining damage from an enemy or hazardous object; instead of dying, the player's rings are scattered. In most Sonic games, a hit causes the player to lose all of the rings, although in certain games a hit only costs a set number of rings such as ten or twenty. When the rings are scattered, the player has a short amount of time to re-collect some of them before they disappear.

Some causes of death cannot be prevented by holding a ring, including being crushed, falling into a bottomless pit, drowning, and running out of time.

In many games, collecting 100 rings usually rewards Sonic or any other playable character an extra life. Certain games in the series often reward the collection of 50 rings with Chaos Emeralds, access to the Special Stages in which the Chaos Emeralds may be obtained, or utilization of a character's super transformation.

Rings have had other uses in various games as well, such as currency (Sonic Adventure 2), restoring health bars (Sonic Unleashed), or improving statistics (Sonic Riders).

Chaos Emeralds
The Chaos Emeralds are, in most games, seven emeralds with mystical powers; they are a recurring feature of Sonic games. The emeralds can turn thoughts into power, warp time and space with a technique called Chaos Control, give energy to all living things and be used to create nuclear or laser based weaponry.

They are the basis of many of the games' plots, and the player is frequently required to collect them all to fully defeat Doctor Eggman and achieve the games' good endings, super forms, or both. The methods used to acquire the Emeralds and the end-results after collecting them differ between games in the series. Most early games require the player to find the emeralds in Special Stages, while some modern games implement the emeralds as a plot element. In certain games, such as Sonic R and the 8-bit versions of Sonic the Hedgehog and Sonic the Hedgehog 2, the player is required to find the Chaos Emeralds within the zones themselves.

The Master Emerald was introduced in Sonic & Knuckles as a plot element. It resides in a shrine on Angel Island and is guarded by Knuckles the Echidna, as only those of the Echidna Tribe are able to control it. The power of the Master Emerald is what keeps Angel Island afloat in the sky. It can control the power of the Chaos Emeralds, including neutralizing or amplifying their energies. In both Sonic Adventure and Sonic Adventure 2, the Master Emerald becomes shattered, requiring Knuckles to find the scattered pieces during his levels.

Special Stages
Usually, Special Stages were employed as a means of earning Chaos Emeralds. Special Stages usually take place in surreal environments and feature alternate gameplay mechanics to the standard platforming of the main levels. The 16-bit Sonic the Hedgehog  consisted of a giant rotating maze, which many considered a major technical achievement. The most common special stages, however, were segments with the character running through a long tunnel to collect certain items. 3D "collect item" levels, as in Sonic 3 and Sonic & Knuckles, used the same perspective but had Sonic collecting all the blue-colored orbs on the surface of a giant sphere. Finally, Sonic Advance 2 employed a 3D ring-collecting stage, and Sonic Chaos (Sonic and Tails in Japan) used a variety of gimmicks for its levels. Since Emeralds of the 8-bit version of Sonic the Hedgehog were hidden in the main stages, the game's spring-filled Special Stages were merely used as a means of adding variety, increasing score and earning continues. Similarly, Sonic 3 & Knuckles, in addition to the main Special Stages, featured entirely optional bonus stages, one of which combined the rotating maze of Sonic the Hedgehog with the pinball gambling of Sonic the Hedgehog 2. Sonic Heroes contained an alternate Special Stage for a chance of earning additional lives.

Super transformation
A super transformation is a state certain characters go into that gives them incredible speed, near-invincibility and a change in color. In some games, characters are still vulnerable to being crushed, drowning, falling into a pit or running out of time. Depending on the type of transformation, the condition to attain such a form is an individual making contact with all of the Chaos Emeralds, the Sol Emeralds, or the Master Emerald.

Super transformations first appeared in Sonic the Hedgehog 2, where Sonic transforms into Super Sonic if all seven Chaos Emeralds and fifty or more rings are held at the same time. While in Super Sonic form, Sonic gains invincibility (except from instant-kill obstacles) and has greatly increased speed. One ring is lost for every second that passes, and Sonic reverts to normal if the number of rings drops to zero. In Sonic 3 & Knuckles, Tails can also transform after gaining all seven Chaos Emeralds and Super Emeralds. Sonic and Knuckles can also transform into their hyper counterparts with the Super Emeralds. Hyper Sonic, Hyper Knuckles, and Super Tails all have unique abilities aside from invincibility and increased speed.

In most 3D Sonic games starting with Sonic Adventure, Chaos Emeralds are collected in non-interactive cut scenes as part of the story, with Super Sonic and other super characters only appearing in the final boss fights. Most 2D Sonic platform games, like the Advance and Rush series, have retained the gameplay-based emerald collecting, but still have Super Sonic only playable in the "Extra" boss battles. Recent games such as Sonic the Hedgehog 4, Sonic Colors, Sonic Generations, and Sonic Lost World once again allow players to play as Super Sonic during normal stages, provided they have all the Chaos Emeralds.

Sonic, Tails, Knuckles, Metal Sonic, Shadow, Blaze, and Silver are the characters that are known to be able to perform super transformations. Metal Sonic can also use the Master Emerald or Chaos Emeralds to turn Super, and Blaze, instead of using the Chaos Emeralds, uses the Sol Emeralds (her dimension's equivalent).

Along with Sonic, Mega Man (fused with the Rush Adaptor) achieved the Super transformation in the Archie Comics crossover Worlds Collide so that the two could restore the damage to their worlds done by Doctor Eggman and Dr. Wily.

Item boxes
These are containers that hold power-ups and appear frequently throughout the stages. An icon on each box indicates what it contains, and the player releases the item by destroying the box. In the early games, item boxes resembled television sets and could only be destroyed with an attack; in later games, they became transparent capsule-like objects easily destroyed with one touch. Common items in boxes include rings, a barrier (or shield), invincibility, high speed (or power sneakers) and 1-ups.

The barrier is a spherical energy shield which surrounds and protects the player's character from one attack; when hit, the barrier is lost instead of rings or a life. In Sonic 3, additional barriers were introduced which gave the player special abilities, such as the ability to magnetically attract rings and double jump, breathe underwater, or resist fire.

Invincibility temporarily protects against damage done by enemies and obstacles, and allows the player to destroy enemies by touching them and not lose any rings. Death from crushing, falling, drowning and time-ups, however, are still possible.

High speed boxes give the player character enhanced speed for a limited time.

1-up boxes display the face of the player's character and give the player one extra life. In the event that a player loses a stage, this enables the player to restart the level at the starting point, or, if one has been passed, close to the last checkpoint. Multiple lives can be collected, generally up to 99.

Other item boxes featured include a box with Robotnik's face on it, which cause damage to whoever opens it, a "teleport box" (Sonic 2's 2-player mode only), which swapped both players' positions, and a skateboard box (Sonic Generations only), which allows the player to ride a skateboard for a short time.

Giant Rings
Giant rings (Warp Rings) were featured in a few Sonic games, mainly from the 16-bit era. Rather than collecting them, as is the case with the smaller ones, they served as a portal to enter a Special Stage, where the player could collect one of the Chaos Emeralds. In Sonic the Hedgehog 3, if all Emeralds have already been found, touching them rewards the player fifty rings. In most games since Sonic Adventure 2, these giant rings serve as the end level marker, which ends the level upon touching it.

Checkpoints
Checkpoints are items placed throughout the stages in Sonic games which serve mainly as progress markers. If the player runs through one, their progress through a level is "saved". If the player then loses a life on the same stage, they will start over at the last checkpoint passed. Checkpoints also serve other uses in various games, such as entering Special Stages in Sonic the Hedgehog 2, and leveling up in Sonic Heroes. In the 2D games, checkpoints take the appearance of posts, while in 3D games they are either small gates or pads on the ground.

Springs
Springs are a staple in the Sonic series. They are scattered throughout the levels and serve to catapult the player at high speeds in a particular direction. Sometimes they allow the player to proceed further in the level, while other times they are used to hinder the player, usually by sending Sonic towards a dangerous area. Sonic Unleashed in particular features springs with Dr. Eggman's face on them that launch Sonic towards danger or hinder his progress. Springs serve as one of Sonic's special moves in Super Smash Bros. Brawl.

Animals
In addition to anthropomorphic animals, the Sonic universe is also populated with more conventional animals. These small animals are often used by Dr. Eggman as "organic batteries" to power his robot armies. The trapped animals can usually be freed by hitting the robot and destroying its metal case. In Sonic Adventure and Sonic Adventure 2, the small animals can be given to Chao, altering their appearance and attributes.

A Flicky is one of the most prominently used animals in Eggman's experiments. This small bird's first appearance in a game predates Sonic. Flicky and its respective game were alluded to in Sonic 3D Blast.

Music
Numerous composers have contributed music to the Sonic the Hedgehog series. Masato Nakamura of J-pop band Dreams Come True was responsible for the music from the first two 16-bit games. Ys/Streets of Rage composer Yuzo Koshiro composed the tunes inspired by the first 8-bit game, except for what was retained from the 16-bit version. Sega's in-house music division, Sega Digital Studios, formerly known as Wave Master, have composed the majority of the music in later games. Jun Senoue, a member of the band Crush 40 and sound director of the series, has written and performed the main theme tunes of both of the Sonic Adventure games, Sonic Heroes, Shadow the Hedgehog, and Sonic and the Black Knight. Since the mid–2000s, the overall sound direction of the series has been handled by Tomoya Ohtani, who has served as the lead composer on Sonic the Hedgehog, Sonic Unleashed, Sonic Colors, Sonic Lost World, and Sonic Forces.

On several recent games, other non-Sega musicians have contributed music to the series. For example, Bowling for Soup lead singer Jaret Reddick performed the main theme of Sonic Unleashed, "Endless Possibilities"; and former Megadeth guitarist Marty Friedman played on "With Me", the final boss theme for Sonic and the Black Knight. Cash Cash lead singer Jean-Paul Makhlouf performed the opening theme to Sonic Colors, "Reach for the Stars", as well as the ending theme, "Speak With Your Heart". Hoobastank frontman Doug Robb performed and wrote the lyrics to the main theme of Sonic Forces, "Fist Bump". The music of electronic dance music (EDM) group Hyper Potions has contributed music to trailers of games in the series, as well as for the soundtracks in Sonic Mania and Team Sonic Racing.

Animation


Sega approached the American Broadcasting Company (ABC) in 1992 about producing two television series—"a syndicated show for the after-school audience" and a Saturday-morning cartoon—based on Sonic. Kalinske "had seen how instrumental the launch of He-Man and the Masters of the Universe cartoon series was to the success of the toyline" during his time at Mattel and believed that success could be recreated using Sonic. The two cartoons, the syndicated Adventures of Sonic the Hedgehog (1993) and ABC's Sonic the Hedgehog (1993–1994), were produced by DIC Entertainment. DIC also produced a Sonic Christmas special in 1996 and Sonic Underground (1999–2000) to tie in with the release of Sonic Adventure. DIC's Sonic adaptations are generally not held in high regard.

Adventures of Sonic the Hedgehog comprised 65 episodes overseen by Ren & Stimpy director Kent Butterworth, and featured slapstick humor in the vein of Looney Tunes. Meanwhile, the 26-episode Sonic the Hedgehog (commonly called Sonic SatAM), inspired by Batman: The Animated Series, featured a bleak setting in which Eggman had conquered the world, while Sonic was a member of a resistance force that opposed him. The series was canceled after two seasons. Sonic Underground was supposed to last for 65 episodes, but only 40 were produced. The series follows Sonic and his siblings Manic and Sonia, who use the power of music to fight against Eggman and reunite with their mother. In all three series, Sonic was voiced by Family Matters star Jaleel White.

Conversely, in Japan, Sega and Sonic Team collaborated with Studio Pierrot to produce a Sonic original video animation (OVA). The two-episode OVA, Sonic the Hedgehog, was released direct-to-video in Japan in 1996. To coincide with Sonic Adventure Western release in 1999, ADV Films released the OVA in North America as a 55-minute film dubbed Sonic the Hedgehog: The Movie. Sonic the Hedgehog, produced with input from Naka and Ohshima, is loosely based on Sonic CD (with certain elements borrowed from Sonic the Hedgehog 2 and 3), and recounts Sonic's efforts to stop a generator taken over by Eggman from exploding and destroying their world. Retrospectively, The A.V. Club Patrick Lee called the OVA "the only cartoon to adapt the look, sound, and feel of the Sonic games", with scenes and music that closely resemble the source material.

Sonic X, an anime series produced by TMS Entertainment and overseen by Naka, ran for three seasons (78 episodes) from 2003 to 2006. While previous series' episodes simply had self-contained plots, Sonic X told a single story that spanned the series' run. In it, the Sonic cast teleports from their home planet to Earth during a scuffle with Eggman, where they meet a human boy, Chris Thorndyke. Throughout the course of the series, Sonic and his friends attempt to return to their world while fighting Eggman. The second season adapts the Sonic Adventure games and Sonic Battle, while the third season sees the friends return with Chris to their world, where they enter outer space and fight an army of aliens. Although Sonic X divided critics * and suffered from poor ratings in Japan, it consistently topped ratings for its timeslot in the US and France.

Sonic Boom, a computer-animated series produced by Sega and Genao Productions, premiered on Cartoon Network in November 2014. It features a satirical take on the Sonic mythos, and the franchise's cast was redesigned for it. According to Iizuka, Sonic Boom came about as a desire to appeal more to Western audiences, and it runs parallel with the main Sonic franchise. To promote the release of Sonic Mania Plus, a five-part series of animated shorts was released on the Sonic the Hedgehog YouTube channel between March 30 and July 17, 2018. The series depicts Sonic's return to his world following the events of Sonic Forces, teaming up with his friends to prevent Eggman and Metal Sonic from collecting the Chaos Emeralds and Master Emerald. The shorts were written and directed by Tyson Hesse, with animation by Neko Productions and music by Tee Lopes. Similarly, Hesse and Neko Productions produced a two-part animated series to tie in with the release of Team Sonic Racing in 2019. Sonic and Tails also appeared as guest stars in OK K.O.! Let's Be Heroes in August 2019.

Live-action film


Efforts to adapt Sonic to film began in August 1994, when Sega of America signed a deal with Metro-Goldwyn-Mayer Pictures and Trilogy Entertainment to produce a live-action animated film to tie in with Sonic X-treme. In May 1995, screenwriter Richard Jefferies pitched a treatment, Sonic the Hedgehog: Wonders of the World, to Sega. The treatment saw Sonic and Eggman escaping from Sonic X-treme into the real world, and Sonic collaborated with a boy to stop Eggman. However, none of the companies could come to an agreement, so the film was canceled. Jeffries, with permission from Sega, pitched his treatment to DreamWorks Animation, but was rejected.

In 2013, Sony Pictures Entertainment acquired the film rights to Sonic the Hedgehog, and in June 2014 announced it would produce a Sonic film as a joint venture with Marza Animation Planet, which helped produce cutscenes for Sonic games. Neal H. Moritz was attached to produce under his Original Film banner, alongside Takeshi Ito, Mie Onishi, and Toru Nakahara. In February 2016, Sega CEO Hajime Satomi stated the film was scheduled for 2018. Blur Studio's Tim Miller and Jeff Fowler were hired the following October to develop the film; Fowler would make his feature directorial debut, while both would executive produce. In October 2017, Paramount Pictures acquired the rights after Sony put the film into turnaround. However, most of the production team remained unchanged.

The film, written by Patrick Casey, Josh Miller, and Oren Uziel, follows Sonic (voiced by Ben Schwartz) as he sets out on a journey to San Francisco with a small-town cop (James Marsden) so he can escape Eggman (Jim Carrey) and collect his missing rings. Additional cast members include Tika Sumpter, Adam Pally, and Neal McDonough. Sonic was initially redesigned for the film so he would be more realistic, with fur, new running shoes, two separate eyes, and a more humanlike physique. The production team used Ted, the living teddy bear from the Ted films, as a reference to insert a CG character into a real-world setting. Sonic's redesign was met with heavy backlash; it was criticized for not resembling the one from the games and described as evoking an uncanny valley-type of repulsive response from viewers. As such, the design was revised so it would better resemble the original.

Paramount originally scheduled Sonic the Hedgehog for a November 8, 2019 release, but delayed it to February 14, 2020, to accommodate the redesign.

Comics and manga
The Sonic the Hedgehog manga series, published in Shogakukan's Shogaku Yonensei, was written by Kenji Terada and illustrated by Sango Norimoto. The manga, which started in 1992, was about a hedgehog boy named Nicky who can turn into Sonic the Hedgehog. Sonic fights Eggman, with Tails tagging along to help him.

Sonic the Hedgehog was an American comic series published by Archie Comics, which has spawned sister series Knuckles the Echidna (discontinued) and Sonic Universe. All of Archie's Sonic-related publications take place in the same fictional universe, which incorporates aspects of the video games and Sonic the Hedgehog: The Animated Series in addition to elements unique to that comic universe. Archie Comics also published a Sonic X comic book that supplemented the animated series of the same name. It began in November 1992 and was originally meant to be a four-part series; however, due to the positive reaction to the series' announcement, it was extended to ongoing status before the first issue premiered. The comic borrowed elements from the animated series' first two seasons and characters from the Sonic Adventure storyline. Some comics were published in the Jetix Magazine, in UK, Italy and Poland. In July 2017, Sega announced that they had ended their partnership with Archie, ending the series of comics after 24 years. Two days later, Sega announced that IDW Publishing would be releasing a new series of Sonic comics, starting in April 2018.

Sonic the Comic was a British comic published by Fleetway Editions between 1993 and 2002. Labeled "the UK's official Sega comic", in addition to Sonic the Hedgehog stories, it also included comic strips based on other Sega games such as Ecco the Dolphin and Decap Attack. The main series of Sonic stories had their own unique storylines and characters in comparison to other Sonic media.

Reception and legacy
The Sonic the Hedgehog franchise was awarded seven records by Guinness World Records in Guinness World Records: Gamer's Edition 2008. The records include "Best Selling Game on Sega Systems", "Longest Running Comic Based on a Video Game" and "Best Selling Retro Game Compilation" (for Sonic Mega Collection). In the Guinness World Records: Gamer's Edition 2010, the Sonic the Hedgehog series was listed number 15 out of the top 50 video game franchises. In September 1996, Next Generation ranked the Genesis installments of the series (but not the Game Gear or Sega CD entries that had been released up to that time) collectively as number 20 on their "Top 100 Games of All Time", calling them "the zeitgeist of the 16-bit era". In December 2006, IGN ranked Sonic the Hedgehog as the 19th greatest series of all time, claiming that "although recent 3D entries in the series have been somewhat lacking, there is no denying the power of this franchise."

Neuroscientists studying the development of the embryonic neural system named a specific set of proteins, in charge of the differentiation of neural tube cells, after the main character of the game franchise.

A common criticism has been that the variant gameplay styles found in recent 3D games have strayed from the formula of the original series. Specifically, the series' jump to 3D has been noted as a declining point. In late 2010, Sega delisted several below-average Sonic games, such as the notoriously disliked 2006 game Sonic the Hedgehog, to increase the value of the Sonic brand after positive reviews for the games Sonic the Hedgehog 4 and Sonic Colors.