I found the game very enjoying, the concept of tactical in a bullet hell and allow the player play at his pace is very appealing to me.
It took me a little to hang the fire control (it is better always being shooting) but not very much and the level design was very good made.
The only little drawback I found was the sound, a bit repetitive and annoying, a background music would had helped a lot, but I remember you said that cannot play background music in pygame so there is little to do there.
A very good submission!
Regards.