Sonic the Hedgehog
The Sega Genesis had "add-on" systems that incorporated "Sonic" games. "Sonic CD", released for the Sega CD, was a 2D platform game released in 1993. The game introduced the characters Amy Rose and Metal Sonic and featured levels that differed depending upon whether Sonic was in the past, present, or future time frames. "Knuckles' Chaotix", a spin-off released in 1995 for the Sega 32X, featured Knuckles and a new group named Chaotix fighting against Dr. Robotnik. The game featured a two-player cooperative system in which the on-screen characters were connected by magic rings. There was also "Sonic Eraser", a puzzle game released exclusively on Sega Game Toshokan in 1991.
Sega Genesis
The Sega Genesis, known as the in regions outside of North America, is a 16-bit home video game console developed and sold by Sega. The Genesis was Sega's third console and the successor to the Master System. Sega released the console as the Mega Drive in Japan in 1988, followed by North America as the Genesis in 1989. In 1990, the console was distributed as the Mega Drive by Virgin Mastertronic in Europe, Ozisoft in Australasia, and Tec Toy in Brazil. In South Korea, the systems were distributed by Samsung as the Super Gam*Boy and later the Super Aladdin Boy.