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 Genesis
In mid-1990, Nakayama hired Tom Kalinske to replace Katz as CEO of Sega of America. Although Kalinske initially knew little about the video game market, he surrounded himself with industry-savvy advisors. A believer in the razor and blades business model, he developed a four-point plan: cut the price of the console, create a U.S.-based team to develop games targeted at the American market, continue and expand the aggressive advertising campaigns, and replace the bundled game "Altered Beast" with a new game, "Sonic the Hedgehog". The Japanese board of directors initially disapproved of the plan, but all four points were approved by Nakayama, who told Kalinske, "I hired you to make the decisions for Europe and the Americas, so go ahead and do it." Magazines praised "Sonic" as one of the greatest games yet made, and Sega's console finally took off as customers who had been waiting for the release of the international version of Nintendo's Super Famicom—the Super Nintendo Entertainment System or SNES—decided to purchase a Genesis instead. Nintendo's console debuted against an established competitor, while NEC's TurboGrafx-16 failed to gain traction, and NEC soon pulled out of the market. In large part due to the popularity of "Sonic the Hedgehog", the Sega Genesis outsold the SNES in the United States nearly two to one during the 1991 holiday season. This success led to Sega having control of 65% of the 16-bit console market in January 1992, making it the first time Nintendo was not the console leader since December 1985.