Sonic World 64 (Original) is a hypothetical ROM hack, similar to the previous entry, which implies that it may be an early or original version of a Sonic-themed game for the N64. It was developed by ROM hackers outside of official Sega or Nintendo development. The 'original' descriptor implies it may be the base version upon which other versions have been built. Gameplay would feature classic Sonic elements, but customized to work within the confines of the base N64 game.  The game would be shared and distributed within ROM hacking communities.

Sonic World 64 (Original)

Sonic The Werehog 64