That was a lot of fun! The different guns were fun to use and having each character ornament on a different level of the tree made it interesting.
My only real issue with the game is the difficulty curve. The game is way too easy. I got to round 16 before even taking a single hit of damage, and the only reason I did was because of a glitch that made it impossible to shoot straight with the 2nd weapon.
I had the most fun when there were a lot of enemies out at the same time and I had to decide what weapons to use and which enemies to take out first.
If you make the difficulty curve steeper, increase the amount of enemies that appear at once, and lower the cooldown for the angel, you've got yourself the foundation for a great little game.