I dig it a lot! Nice style and love the colors. Good bullet patterns with a solid challenge. Love the sound on that big green laser guy too! Bravo for adding an autofire option in the menu, thank you!
The only thing I found myself waiting for was power-ups during the level. I get it's a big reward from each boss but getting those upgrades as you go (and then maybe losing them) can add a lot to the experience. Getting them only with the boss and then losing them after one mistake made me not really care if I get them at all.