Sonic the Hedgehog (Prototype) - Hidden Palace

A prototype of Sonic the Hedgehog for the Sega Mega Drive.

Hidden Palace Zone (Sonic the Hedgehog 2), Sonic Wiki Zone

Genesis / 32X / SCD - Sonic the Hedgehog (Prototype) - Sparkling Zone - The Spriters Resource

Proto:Sonic the Hedgehog 2 (Genesis)/Simon Wai Prototype - The Cutting Room Floor

Sonic the Hedgehog (Prototype) - Hidden Palace

Sonic Origins: How to Unlock Hidden Palace Zone

Secrets of Sonic Team=

Sonic the Hedgehog 2 Prototypes (Sega Genesis / Mega Drive)

CENSOR Prototype of Sonic 2 Rediscovered by Hidden Palace - Sonic Retro

News/Sonic Month Part 5 - Before Hard Times - Sonic 3 (MD) - Hidden Palace

Sonic the Hedgehog 2 (PROTOTYPES) LOST BITS Cut Content & Unused Zones [TetraBitGaming]