Sonic 1 SCP 001 (When Day Breaks) Edition is a fan-made ROM hack of Sonic the Hedgehog for Sega Genesis, themed around the SCP Foundation and its 'When Day Breaks' narrative. The original Sonic the Hedgehog was released by Sega in 1991.  This hack likely incorporates elements from the SCP Foundation lore into the game's levels, story, or characters. The developers, independent of Sega and the SCP Foundation, have created a unique crossover experience. 

Sonic 1 SCP 001 (When Day Breaks) Edition

Sonic 1 Remastered v1.1