Sonic 20th Anniversary

Sonic 20th Anniversary is an app in the App Store for iPhone, iPad and iPod Touch.

Sonic the Sketchhog
Sonic the Sketchhog is a minigame in the app. It is a 2D sidescroller platform game. The game features Sonic in a handdrawn doodle style defeating badniks like Crabmeat as he advances his way though a drawn level.

Sonic the Hedgehog 4 Demo
There is also a demo of Sonic 4.

Special
SEGA put here special iPhone wallpapers. The wallpapers are only available for limited time of 2 weeks (except for the special 20th anniversary wallpapers).