It took a little longer than planned so i'm a tad late for Sonic's 20th birthday, but I finally finished it.
Every zone from "Sonic 1":http://en.wikipedia.org/wiki/Sonic_the_Hedgehog_%28video_game%29, "2":http://en.wikipedia.org/wiki/Sonic_the_Hedgehog_2_%2816-bit%29 & "3":http://en.wikipedia.org/wiki/Sonic_the_Hedgehog_3 arranged into the shape of "Sonic":http://en.wikipedia.org/wiki/Sonic_the_Hedgehog_%28character%29, "Tails":http://en.wikipedia.org/wiki/Tails_the_Fox & "Knuckles":http://en.wikipedia.org/wiki/Knuckles_the_Echidna respectively; Sonic has "all the zones from Sonic the hedgehog":http://sonic.wikia.com/wiki/Sonic_the_Hedgehog_%281991%29#Zones (as that game was his debut), Tails has "all the zones from Sonic 2":http://sonic.wikia.com/wiki/Sonic_the_Hedgehog_2#Stages (his debut game) & Knuckles has "the zones from Sonic 3":http://sonic.wikia.com/wiki/Sonic_the_Hedgehog_3#Zones (his debut game).
If you like this, check out my original "Sonic the hedgehog design":http://www.redbubble.com/people/photosmagoria/t-shirts/4693819-sonic-the-hedgehog. Also check out my "Sonic, Tails & Knuckles sticker set":http://www.redbubble.com/people/photosmagoria/t-shirts/7437598-sonic-tails-and-knuckles if you're after something simpler. You can also pick up my "Sonic the Hedgehog":http://www.redbubble.com/people/photosmagoria/t-shirts/7916910-sonic-the-hedgehog design as an Iphone4/4S case.
All done in photoshop CS5.