Sonic 2 in 1 consists of two Game Gear titles in a single cartridge. As a unique function to most compilations, this game does not feature a menu screen or game select screen. Instead, the cartridge automatically alternates between the two games upon booting up.
To this day, Sonic 2 in 1 is a rare game package, even around the Internet on websites such as eBay due the original release being European-exclusive. Later compilation titles since then have had a menu to switch games.