Sonic the Hedgehog - SteamGridDB

Sonic the Hedgehog (1991 video game) - Wikipedia

Accurate Sonic 1/CD Sprites

Sonic the Hedgehog [Master System/Game Gear] (video game, 2D platformer, science fiction, fantasy) reviews & ratings - Glitchwave

Custom / Edited - Sonic the Hedgehog Customs - Sonic (Sonic 1 SMS

Sonic SMS Remake: Sonic 1

Sonic 1 Blastless : vladikcomper : Free Download, Borrow, and

3D Sonic the Hedgehog

Release][N3DS] Sonic 1 & 2 (2013) Decompilation port

I'm learning to use the SGDK, I made these edits for Sonic 1 and 2

S1F EP (Sonic 1 Forever Expansion Pack) (ARCHIVED) : Expansion