New Sonic the Hedgehog (1991) prototype uncovered by preservation

A prototype of Sonic the Hedgehog (1991) was showcased by a video game preservation group in a New Year's Eve livestream.

Long Lost Sonic The Hedgehog Prototype Finally Released

7 Sonic The Hedgehog Prototypes You Were Never Meant To Play

UPDATE: Claimed Sonic 1 Prototype Footage Goes Online

Sonic the Hedgehog (Prototype) LOST BITS

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

A Sonic 1 Prototype for the Sega Mega Drive Has Been Found After

Long lost Sonic the Hedgehog 1 prototype discovered

Sonic the Hedgehog (lost Winter Consumer Electronics Show 1991

Sonic the Hedgehog (lost Tokyo Toy Show prototype build of Sega

Random: Fan Discovers A Bunch Of Cool New Hacks Inside Sonic 3D

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

New Sonic game prototypes found by drx, shows early stages from

Sonic 2 'lost stages' discovered via old design docs and a VHS

Sonic Origins - Wikipedia