Timing: Seems okay to me.
Easy: I think the beats that come straight after the spinners are a bit too challenging for the audience who are going to be looking to play the Easy games. Probably shorten the spinners a little so they have a chance to get their bearings.
Medium: Can't find any faults, though there was one tricky section where the beats are weird but it matches the song so I think it's all right to leave it.
Hard: No suggestions.
Insane: No suggestions.
Nutty: At 0:22:60 and 0:24:00 you have different rythms going and I wasn't sure if you wanted them to both be the same or different.