Red Sonic in Sonic 2 is a ROM hack modification of Sonic the Hedgehog 2 for the Sega Genesis. It introduces a red-colored Sonic character, potentially with changes to game mechanics or character abilities.  This is not an official Sega release but instead a fan-made project that alters the original game's content. The creator and specifics would need further research within the ROM hacking community.

Red Sonic in Sonic 2

Rastan Saga II (USA)