I barely got to the darn boss. Then it was "Make two happy" or whatever. I'm done. Throwing in the towel. Quitters might never win, but they do get sleep.
I give it a 3/5. Would be a 4, or even a 5, but the scoring that doesn't really accomplish any measure is bad. There needs to be a time, or a "par" number of moves.
I think for a game like this to really be entertaining, you need a score, and bonus points for clearing the same piece again and again. Just my 2 cents.