is a 1991 platform video game in the
Sonic the Hedgehog series that was released on October 25, 1991 for the
Sega Master System and on December 28, 1991 for the
Sega Game Gear. Developed by
Ancient, it is the distinct 8-bit version of the more popular
16-bit game. In addition to its original release as a cartridge, the game was later built into some versions of the Sega Master System II in
Europe. It was the last game released for the Sega Master System in
North America.