Sonic The Hedgeblog — In early 'Sonic 1′ screenshots the Green Hill Zone

In early ‘Sonic 1′ screenshots the Green Hill Zone flowers were purple. In the @HiddenPalaceOrg prototype you can see it for yourself.

Green Hill Zone screenshots, images and pictures - Giant Bomb

Sonic Mania - Page 40 - Discussion - rllmuk

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

New Sonic Mania Screenshot Showcases Green Hill Zone Act 2 – SoaH City

Modder adds new features to Sonic Advance on Android

Community – The Sonic Stadium

Sonic The Hedgeblog

LEGO IDEAS - Blog - 10K Club Interview: Viv Grannell's Sonic Mania Green Hill Zone! (Best enjoyed with a Chili Dog)

sonicadventure #dreamcast #sega #sonic #sonicthehedgehog

S1 LE - Green Hill Zone Act 1 (Old Screenshot) by MarioYT21 on DeviantArt

Sonic the Hedgehog (1991 video game) - Wikipedia

Sonic Generations – First Screenshots And Trailer Revealed!

Zone: 0 > Sonic 1 > Green Hill Zone