Gammix bobs to the music: three frames of him, each a pixel shorter in the legs, chosen by where the song is in its beat with song.beat: down on the beat, up before the next. Every four bars he turns round once, started by onBeat. Both go by what is heard, so he stays in time at any tempo.
The arrows left and right change the song, up and down the tempo, and space plays it or stops it.