
Sonic CD features the debuts of the recurring Sonic characters Amy Rose and Metal Sonic, and includes animated cutscenes. Led by Sonic 's co-creator Naoto Ohshima, the developers sought to show off the technical capabilities of the Sega CD. Sonic CD began as a port of the Sega Genesis game Sonic the Hedgehog (1991), but developed into a separate project.

By traveling through time, players can access different versions of stages, featuring alternative layouts, music, and graphics. Sonic CD introduces time travel as a game mechanic.

Like other Sonic games, Sonic runs through themed levels while collecting rings and defeating robots. As Sonic the Hedgehog, the player attempts to protect an extraterrestrial body, Little Planet, from Doctor Robotnik. Sonic the Hedgehog CD is a 1993 platform game developed by Sega for the Sega CD.
