Sonic 3 & Knuckles - The Cutting Room Floor

Unused Localized Version of SegaSonic the Hedgehog (Source from The Cutting Room Floor)

Sonic 3 Prototype With Lost Content Discovered

Proto:Sonic the Hedgehog 3 - The Cutting Room Floor

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

Proto:Sonic the Hedgehog (Genesis) - The Cutting Room Floor

Review: The History of Sonic The Hedgehog – Destructoid

Sonic the Hedgehog 2 - Plugged In

Sonic the Hedgehog 2 Gets the Remastering Treatment, With the Long-Lost Hidden Palace Level Restored

Sonic 3 Prototype With Lost Content Discovered - IGN

Sonic the Hedgehog 3 - The Cutting Room Floor

Sonic Mania LOST BITS Unused Content and Debug Mode Secrets [TetraBitGaming]

Sonic the Hedgehog 3/Hidden content - Sonic Retro

Sonic the Hedgehog LOST BITS Unused Content and Debug Mode & Knuckles [TetraBitGaming]