Sonic Remastered v0.1 indicates a version number, suggesting it's a work-in-progress ROM hack. This ROM hack likely modifies the original Sonic the Hedgehog for Sega Genesis. The gameplay would be based on the original, but with changes made by the creators.  It is a project created outside of Sega's official development and is likely part of the ROM hacking community.

Sonic Remastered v0.1

Sonic Remastered (S1 Hack)