Press spacebar to change backgrounds, click < or > to rotate (not the keyboard options.) Check the notes :3
Story: Sonic: hey Darthon i know how much you wanna get stronger, so why don't we train! Darthon: ...heh you sure cause ive gotten a lot stronger since we last trained. Sonic: sure i'm sure, this time i'll win! Darthon: heh don't get cocky little brother