Sonic Chaos (May 17, 1993 prototype) - Hidden Palace

A prototype of Sonic Chaos (also known as Sonic & Tails in Japan) for the Sega Game Gear.

Sonic Hacking Contest :: The SHC2022 Contest :: Sonic the Hedgehog

Sonic The Hedgehog Series (Alternate Timeline)

Early Sonic 3 prototype found, features major differences to the

Sonic The Hedgeblog — From @HiddenPalaceOrg's May 17, 1993

Retro Gamer No. 175 (Digital)

Sonic Chaos (Game Gear prototype; 1993-05-17) - Sonic Retro

Sonic Chaos (Jun 30, 1993 prototype) - Hidden Palace

Proto:Sonic the Hedgehog 3 - The Cutting Room Floor

Sonic Prototypes (released by Hidden Palace)