Sonic the Hedgehog [1991]

Sonic the Hedgehog (lost Winter Consumer Electronics Show 1991 demo build of Sega Genesis/Mega Drive platformer; 1991) - The Lost Media Wiki

Retro Review: Sonic The Hedgehog #1 (Fall 1991) — Major Spoilers — Comic Book Reviews, News, Previews, and Podcasts

Sonic the Hedgehog (1991) – Movie Reviews Simbasible

History of Sonic the Hedgehog by Sega Genesis

Sonic 1 and 2 3DS - GameBrew

Sonic The Hedgehog Classic on the App Store

Sonic the Hedgehog 1991 to 2011 by 9029561 on DeviantArt

New Sonic the Hedgehog (1991) prototype uncovered by preservation groups - Tails' Channel

SEGA AGES Sonic The Hedgehog for Nintendo Switch - Nintendo Official Site

SEGA AGES Sonic The Hedgehog 2 for Nintendo Switch - Nintendo Official Site

Sonic the Hedgehog 1991 (Full Game)

Sonic the Hedgehog : Unknown: Video Games