OUCH THE MUSIC. Seriously, it felt like someone was applying a drill to my brain.
Other than that, I didn't hit any glitches, so that was nice. I wish there was a bit more feedback when you got hit (Maybe there was a chime or a beep or something; I couldn't hear it over the music).
I didn't really have fun, though, because the robot's hitbox seems to be a bit too big, and it moves a bit slowly, so the game got a lot of cheap hits in :p. If either of those issues were fixed, I think it would be a great deal more enjoyable.