Good, cept for one thing......
The lag is shocking once you hit Lv25... and at 35 it was unplayable. However one thing I noticed, is that it lags badly even when very few shapes are on the screen, and I just have 1 rocket and my main gun. I have a suspicion that you are either creating a billion entities of the shapes before each level, or that the particle effects of the shapes exploding are not properly removed, either way thats really bad optimization, and its the only reason I can think of that im lagging with barely any instances on the screen at all.