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
As a result of piracy in some countries and unlicensed development issues, Sega incorporated a technical protection mechanism into a new edition of the Genesis released in 1990, referred to as the Genesis III. This new variation of the Genesis included a code known as the Trademark Security System (TMSS), which, when a game cartridge was inserted, would check for the presence of the string "SEGA" at a particular point in the memory contained in the cartridge. If the string was present, the console would run the game, and would briefly display the message: "" This system had a twofold effect: it added extra protection against unlicensed developers and software piracy, and forced the Sega trademark to display when the game was powered up, making a lawsuit for trademark infringement possible if unlicensed software were to be developed. Accolade learned of this development at the Winter Consumer Electronics Show in January 1991, where Sega showed the new Genesis III and demonstrated it screening and rejecting an "Ishido" game cartridge. With more games planned for the following year, Accolade successfully identified the TMSS file. It later added this file to the games "HardBall!", "Star Control", "Mike Ditka Power Football", and "Turrican".