I really like the concept although it took me way too long to realize you could choose different colors of bowling balls.
One thing that was really annoying was that you get hit from behind without being able to do muck about it way too often. Maybe it would be better in 3rd person so you can see behind yourself? Or you could make it so the enemies mostly spawns from one direction.
Still a cool game though. I especially found it amusing how the enemies falls over when you hit them.