I like bouncing off the walls, and I do like the sound effects. The gray background gives me this "unfinished" vibe though for some reason.
I took me to wave 8 to die, so I didn't get to see the "out of control" aspect till later on. Maybe if the health was lower, and less health pickups?
I think a simple addition that would make sacrificing a lot more compelling is displaying my score somewhere, so I'd want to keep going to improve my score. Maybe the score could have a multiplier based on how many controls have been sacrificed?