This was a lot of fun! Clean and well put together. Those jumping purple guys are super nasty! If they get you once I couldn't get enough space away from them to effectively kill them.
I got stuck at one point because I thought that all the doors would show up on my map, but maybe they only appear after you use them once? Also, I fired off all my missiles and went around the loop killing all the enemies twice and I never got more missiles. Was I missing something? I'll have to come back and play again later.