Editing Sonic the Hedgehog (1991) (section)

===Gameplay and programming===
Having completed their protagonist, Sega would turn to Yuji Naka, a programmer who had impressed them with his work on ''[[Wikipedia:Phantasy Star (video game)|Phantasy Star]]'' and the Mega Drive port of ''[[Wikipedia:Ghouls 'n Ghosts|Ghouls 'n Ghosts]]''.<ref name="retro" /> With Naka himself ironically being a fan of ''[[Wikipedia:Super Mario Bros.|Super Mario Bros.]]'', but desired something with a faster gameplay, the game was made to play quickly,<ref name="RGBoom">{{cite journal|journal=Retro Gamer Sega Archives|date=2016|publisher=Imagine Publishing|location=Bournemouth|isbn=978-1-78546-372-3|pages=50–59|title=Sonic Boom: The Success Story Of Sonic The Hedgehog}}</ref> which was where Naka focused most of his effort.<ref name=NakaInt>{{Cite book|author=[[Yuji Naka]]|year=2014|title=Yuji Naka Game Designer|work=Sega Mega Drive/Genesis Collected Works|publisher=Read-Only Memory|pages=278-279|isbn=978-0-9575768-1-0}}</ref> Naka explained that the reason he wanted a fast game was that he had ported ''Ghouls 'n Ghosts'', and wanted to work on its movement, but found it slow.<ref name=NakaIntHist>{{Cite book|author=[[Yuji Naka]]|year=2013|editor=Les Editions Pix'n Love (ed.)|title=Interview With Yuji Naka|chapter=The History Of Sonic The Hedgehog|publisher=UDON Entertainment Corp|pages=90–95.|isbn=978-1-926778-96-9}}</ref>

The game that would become ''Sonic the Hedgehog'' was developed by a team of seven: two programmers, two sound engineers, and three designers,<ref name=NakaIntHist/> although it began with just Naka and Ohshima.<ref name=OhshimaIntHist/> People came onto the team as content for the game increased.<ref name=OhshimaIntHist/> After being assigned a project with the code name "Defeat Mario", Naka and Ohshima began working together on the game. However, they eventually encountered problems: Ohshima's Rabbit proved hard to program. In addition, catching items and throwing them broke the action's rhythm. Furthermore, Naka stated that the rabbit was not suitable for his game engine and that he wanted the game to be playable with only one button. As such, [[Hirokazu Yasuhara]] joined the team to supervise Naka and Ohshima and develop levels. Eventually, his greater experience led to him becoming the game's lead designer. He also found the way to make the game playable with only one button by having Sonic [[Spin Jump|do damage while jumping]]. From there, the trio came up with the idea of Sonic [[Spin Attack|rolling into a ball]]. After the hedgehog character was chosen, many characters were redrawn, and the team agreed on the environments' visual complexity, with particular focus on the colors. After this, four people came onto the team to speed up the development.<ref name="Zone1">{{cite book|editor=Les Editions Pix'n Love|title=The History Of Sonic the Hedgehog|date=2013|publisher=UDON Entertainment Corp|location=Ontario|isbn=978-1-926778-96-9|pages=20–33|chapter=Zone 1 Genesis}}</ref>

Because of Mario's popularity, Naka wanted Sonic to take over the American market. Sonic's default speed was set to be that of Mario while running. Tests were run using the Mega Drive's tool library, and problems such as flickering, slow frame rates, and shaky animation soon became apparent. In addition, increasing Sonic's speed caused animation problems. However, Naka would solve this issue by developing an algorithm that would retain fluidity. At the end, all that was left was to optimize the game speed to adhere to the staff's expectations. However, the team noticed that different people had different perceptions of the game's speed: some believed it was too fast, which caused disagreements. Ultimately, it was decided to slow the game's pace down.<ref name="Zone1"/>

The gameplay originated with Naka's tech demo, who developed an algorithm allowing a sprite to move smoothly on a curve by determining its position with a [[Wikipedia:dot matrix|dot matrix]]. Naka's prototype ended up involving a platform game with a fast-moving character rolling in a ball through a long, winding tube. This concept would be fleshed out with Ohshima's character designs and levels by Yasuhara.<ref name="Yasuhara">{{Cite journal|author=GI Staff|date=August 2003|title=Sonic's Architect: GI Interviews Hirokazu Yasuhara|journal=[[Wikipedia:Game Informer|Game Informer]]|issue=124|pages=114–116}}</ref> Originally, Yasuhara wanted to work on the game for three months due to the delay of his planned move to the United States by the outbreak of the [[Wikipedia:Gulf War|Gulf War]]. However, he ended up being engrossed in the project for nearly a year.<ref name="Yasuhara"/><ref name="Birth">{{Cite journal|last=Thomason|first=Steve|date=January 2007|title=Birth of a Hedgehog|journal=[[Wikipedia:Nintendo Power|Nintendo Power]]|issue=211|publisher=[[Wikipedia:Future Publishing|Future Publishing]]|page=72}}</ref> His designs for levels were intended to attract both hardcore and casual gamers by integrating occasional challenging set pieces into the mostly accessible level design.<ref name="retro"/> The color scheme was influenced by the work of pop artist Eizin Suzuki, and the aesthetics of [[Green Hill Zone (Sonic the Hedgehog)|Green Hill Zone]] were influenced by the geography of [[Wikipedia:California|California]].<ref name="retro"/>

When it came to designing the gameplay, Naka was ironically inspired by [[Wikipedia:Shigeru Miyamoto|Shigeru Miyamoto]], the creator of the ''Super Mario'' games, whose games he had enjoyed playing years earlier. Admiring the simplicity of Miyamoto's mechanics in complex environments, Naka decided that Sonic would be controlled with only a directional pad for movement and a single button for jumping. He also wanted his creation to be more action-oriented than the ''Mario'' series;<ref name="edge">{{Cite journal|title=The Making of ... Sonic The Hedgehog|journal=[[Wikipedia:Edge (magazine)|Edge]]|issue=101|publisher=[[Wikipedia:Future plc|Future Publishing]]|date=September 2001|pages=118–121|issn=1350-1593|quote=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.}}</ref> while playing ''Super Mario Bros.'', he would wonder why the game's levels could not be cleared faster.<ref name="retro"/>

Over time, Naka, Ohshima, and Yasuhara would work nineteen hours a day on the project for several months.<ref name="Yasuhara"/> Due to the need to demonstrate the Sega Mega Drive's technological prowess, the game underwent extensive testing and redesign, which took over six months. According to Naka, the game had the fastest-ever character speed in a video game and a rotation effect in the [[Special Stage (Sonic the Hedgehog) (16-bit)|Special Stages]] that had been considered impossible on the console.<ref name="edge"/>

The team originally intended to add a two-player mode displayed via [[Wikipedia:split screen (computer graphics)|split-screen]], but Naka's programming knowledge was not enough to implement it. However, a two-player mode would appear in ''[[Sonic the Hedgehog 2]]'', whereby the second player would control Sonic's sidekick, [[Miles "Tails" Prower]].<ref name="retro"/> Sonic Team also intended to include a [[Sound Test]] with animations of Sonic breakdancing to a band of animal characters, dubbed the [[Sonic the Hedgehog Band]]; including a crocodile keyboardist who was later introduced to the series as [[Vector the Crocodile]] in ''[[Knuckles' Chaotix]]''.<ref name="soundtest">{{cite web|url=http://xbox.gamespy.com/articles/654/654750p5.html|title=Sega's Yuji Naka Talks!|last=Kemps|first=Heidi|date=30 September 2005|publisher=[[Wikipedia:GameSpy|Gamespy]]}}</ref> In the end, the Sound Test was scrapped due to time reasons and Naka used the freed up memory to add the "''Se-ga!''" chant used in TV commercials as a start-up sound.<ref name="soundtest"/>

[[File:S1concept-eggman.jpg|thumb|left|225px|One of the concepts for the hero of what eventually would be known as ''Sonic the Hedgehog''. This character would later be slightly modified to become the main antagonist of the game, [[Doctor Eggman|Dr. Eggman]].]]
Unfortunately, Naka's relationship with Sega was tenuous during this time, and he received little credit for his work. He left the company shortly after the game's release, although Sega of America hired him later. Before leaving, however, he defied Sega's prohibition of developer credits by displaying a few names in black text on a black background, identifiable only by looking at the code.<ref name="facts"/> Naka stated that level design was a major challenge: he created maps much wider than normal and tried to ensure players would not get lost. It took him around eight months to develop Green Hill Zone as he kept restarting from scratch.<ref name=NakaInt/><ref name="Zone1"/> He stated that he found the process "very interesting".<ref name=NakaInt/> Naka also stated that the team was trying to create smooth maps, and that implementing looping structures was a challenge because Sonic would break through them instead of running around them. The backgrounds were also a challenge, as the game's speed created the impression of going backwards.<ref name=NakaIntHist /> The [[Zone]]s were based on designs by Naka and Ohshima, with the goal of creating the world's fastest action game. According to Ohshima, Eggman was based on [[Wikipedia:Humpty Dumpty|Humpty Dumpty]].<ref name="OhshimaInt">{{Cite book|author=[[Naoto Ohshima]]|year=2014|chapter=Naoto Ohshima Visual Designer|title=Sega Mega Drive/Genesis Collected Works|publisher=Read-Only Memory|pages=328-329|isbn=978-0-9575768-1-0}}</ref>

Yasuhara wanted the game to appeal to both Japanese and American players, which led to Green Hill Zone being redesigned many times. Sonic Team also wanted the level to portray the character correctly. Its checkered ground was inspired by 3D image rendering from computers, an idea Naka obtained from Sega developer [[Wikipedia:Yu Suzuki|Yu Suzuki]], who used this technique with ''[[Wikipedia:Space Harrier (video game)|Space Harrier]]''. The team read ''[[Wikipedia:Famitsu Magazine|Famitsu]]'' magazines to stay informed of what their rivals were doing so they could avoid their mistakes.<ref name="Zone1"/>