Hivebrain's hack, "Sonic the Hedgehog Plus," enhances the original Sega Genesis game. The exact nature of "Plus" isn't specified, but it implies additional content or improved features. This could range from graphical improvements to new levels, gameplay mechanics, or difficulty adjustments.  This community-made modification represents the drive to improve and expand upon existing classics.

Sonic the Hedgehog (USA, Europe) [Hack by Hivebrain v0.20] (~Sonic the Hedgehog Plus)

Sonic the Hedgehog (USA, Europe) [Hack by Carretero v2.0] (~Sonic - Return to the Origin) (Backward Play)