Sonic the Hedgehog
Due to the success of "Sonic" games on the Sega Genesis, the series was introduced to the Master System and the Game Gear. Sega began by releasing "Sonic the Hedgehog", a 2D platform game, in 1991. The game featured Sonic's ability to run and to jump at high speeds like its Mega Drive/Genesis counterpart but with notably different level design and music. Sega later released "Sonic the Hedgehog 2" another 2D platform game, in 1992. The game differed from its Genesis counterpart with different levels and music and by not including a "spin dash" maneuver. It also featured a different storyline in which Doctor Robotnik kidnaps Tails, who is non-playable in the Master System/Game Gear version. "Sonic Chaos"/"Sonic and Tails" (Japan), released in 1993, was similar to the earlier two Sega Master System/Game Gear "Sonic" games, but featured Tails as a playable character. A sequel, "Sonic Triple Trouble"/"Sonic and Tails 2" (Japan), a 2D platform game, was released in 1994 for the Game Gear and introduced a new character, Nack the Weasel, who, along with Knuckles and Doctor Robotnik, raced to collect the Chaos Emeralds. One of the last games for the Sega Game Gear, "Sonic Blast", was released in 1996 and featured prerendered sprites.
Sega
For the North American market, where the console was renamed Genesis, former Atari executive and new Sega of America CEO Michael Katz developed a two-part approach to build sales. The first part involved a marketing campaign to challenge Nintendo head-on and emphasize the more arcade-like experience available on the Genesis,with slogans including "Genesis does what Nintendon't". Since Nintendo owned the console rights to most arcade games of the time, the second part involved creating a library of recognizable games which used the names and likenesses of celebrities and athletes. Nonetheless, Sega had difficulty overcoming Nintendo's ubiquity in homes. Tasked by Nakayama to sell one million units in the first year, Katz and Sega of America sold only 500,000.As Sega sought a flagship series to compete with Nintendo's Mario series, and a character to serve as a company mascot, artist Naoto Ohshima designed "a teal hedgehog with red shoes that he called Mr. Needlemouse". This character was renamed Sonic the Hedgehog, creating one of the best-selling video game franchises in history. 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 prototype was a platform game that involved a fast-moving character rolling in a ball through a long winding tube; this concept was fleshed out with Ohshima's character design and levels conceived by designer Hirokazu Yasuhara. Sonic's blue color was chosen to match Sega's cobalt blue logo. His shoes were inspired by Michael Jackson's boots, and his personality by Bill Clinton's "can-do" attitude.