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.
Sonic the Hedgehog (1991 video game)
Sega of America CEO Tom Kalinske wanted reassurance that the character would not fail. The global head of marketing, Al Nilsen, became involved, and playtested the game across the United States with Mario fans: they were shown "Mario" and then played "Sonic the Hedgehog". 80 percent preferred "Sonic the Hedgehog", and the game was shown at the 1991 Summer Consumer Electronics Show. It was released in North America on June 23, 1991, and in the PAL regions and Japan the following month. Sega of America packaged it with American Genesis consoles, replacing "Altered Beast". This tactic enabled Sega of America to sell 15 million Genesis units. Genesis owners who bought their consoles before the switch could request free copies of "Sonic the Hedgehog" by mail. Sega of America created a large-scale marketing campaign, promoting Sonic as its mascot.