Sonic Poopy is a ROM hack of the original Sonic the Hedgehog for the Sega Genesis. Details about its development history and creators are scarce, but it's categorized as a modification altering Sonic's game levels and potentially other aspects. The gameplay would retain the core mechanics of the original Sonic,  but with modified levels and potentially changes to Sonic's abilities or enemy placements.  It's a fan-made creation, not officially produced by Sega or any major game company.

Sonic Poopy

Sonic Night Edition (S1 Hack)