Sonic CD is a remastered version of the classic game that was originally released for the Sega Genesis console in the early 90s. It is a side-scrolling 2D platformer where the main goal of the player is to go as fast as possible. The game is often considered the best in the series and has been re-released on various platforms.

The game's plot involves Sonic rescuing the extraterrestrial body Little Planet from the clutches of Dr. Robotnik, who has tied it to a mountain and turned it into a factory. The game features classic gameplay elements such as completing levels and defeating bosses, with special levels becoming available after collecting 50 rings. The remastered version includes the ability to play in 16:9, leaderboards, and achievements.