I loved the game. I thought it was too easy at the start, but that was exactly why I was wrong. XD
That's a clever way to make the player feel weaker, especially since you have to get to keep only one thing from each level down. So in a way you develop your strategy based on what enemies you want to focus first. Also near the end I noticed they follow patterns, so you can even play around that if you prepare carefully. Also, good use of the defense command. C:
Really, a pretty cool game!