Wow, hadn't seen a Barfquestion thing in quite a while! :)
A fun arcade style game, I found it pretty 'mindless' in a good way, if that makes any sense. just running really fast through the screen hitting a ball or something with your racket and bringing chaos into the building. I really liked the fact that the ball was then replaced with the stuff you fonund, and the fact that it had boss battles and related cutscenes kept it fresh.
If I had to point out an issue, it could be that at some points the pacing is a bit lost when there isn't much left to do in the level but you still got to take care of it, which means there isn't much 'danger' or anything that could treathen your control of the ball (or whatever you're using), I found this more noticeable on the first levels, since it became more diverse later in the game.