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.
Video game console
The Nomad was released in October 1995 in North America only. The release was five years into the market span of the Genesis, with an existing library of more than 500 Genesis games. According to former Sega of America research and development head Joe Miller, the Nomad was not intended to be the Game Gear's replacement and believes that there was little planning from Sega of Japan for the new handheld. Sega was supporting five different consoles: Saturn, Genesis, Game Gear, Pico, and the Master System, as well as the Sega CD and 32X add-ons. In Japan, the Mega Drive had never been successful and the Saturn was more successful than Sony's PlayStation, so Sega Enterprises CEO Hayao Nakayama decided to focus on the Saturn. By 1999, the Nomad was being sold at less than a third of its original price.