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 Prototypes (released by Hidden Palace)

Sonic the Hedgehog/History and appearances (2007 - present

Sonic Chaos (May 17, 1993 prototype) - Walkthrough

Sonic the Hedgehog 2 - Wikipedia

Sonic CD - Wikipedia

Sonic the Hedgehog 2 - Wikipedia

Sonic Prototypes (released by Hidden Palace)

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

Sonic Chaos (June 30, 1993 Prototype) :: First Look Gameplay (720p

Sonic Chaos (Jun 30, 1993 prototype)