Green Hills Zone Sonic News Network+BreezeWiki

The Green Hill Zone: Engine Test (Sonic Engine GameMaker Fangame) by Ashleydev - Game Jolt

Sega Genesis / 32X - Sonic the Hedgehog (Prototype) - Green Hill Zone Act. 1 (Dark) - The Spriters Resource

Green Hill, Sonic Wiki Zone

Green Hill Zone (Sonic the Hedgehog 16-bit) - Sonic Retro

Steam Workshop::Green Hill Zone Act 1

Green Hill Zone Act 1 by Unknow_rpg

Fastest Time To Complete Green Hill Zone Act 1 In Sonic The Hedgehog, World Record

Sonic 1 Stages - Nerd Bacon Magazine

Pixilart - Green hill zone act 1 by Gamer2312

Worms Map Database - Maps - Sonic Mania - Green Hill Zone - Act 1