Synchronization is poor for this kind of a game. The arrows reach the line noticeably before the relevant beat. It still works to hit them at the auditorily correct time (they are just barely still touching the line before going above it), but the disconnect between the visuals and the audio is fairly disconcerting to something with good coordination.
Bugs on 38 are really ticking me off. I know how to solve the puzzle, but boxes keep going into the portals and coming out in a different place that is not near a portal. I have to kill myself and start over every time! Reduced my rating from 5/5 to 3/5 because of the bugs.
I can't figure out how to attack with my crossbow. Spacebar makes Firefox scroll down a screen so I can't see the game. Numpad 0 doesn't do anything. Watching my troops kill the badguys for me is boring.
Has trouble with lag ... shapes fall just as fast, but gun slows down. This means gameplay/results are different on different machines. When short on time the engine should reduce animation frames but shoot just as fast.