Sonic Mega Mix (S1 Hack) is a hack or modification of the original Sonic the Hedgehog game for the Sega Genesis. The 'S1 Hack' designation specifies it's built upon the first Sonic game. Fan-made games like this use the existing game engine and assets to create new levels, gameplay mechanics, or story elements. The details are specific to this particular hack.

Sonic Mega Mix (S1 Hack)

Sonic Maxidrive (2023 Demo)