Well put together game! Solid music, art, and gameplay. The controls were a little hard to figure out, and I still don't know why sometimes I can't place a ranged unit in a given location at one point, then later on can.
The learning curve was a bit hard at first, even though I read the how to on the title screen. It would've been useful to be able to access it through the pause menu.
Switching back and forth between keyboard controls and mouse controls wasn't a good experience, though it's one I'm guilty of in my game as well!
I liked stage 1-3, where they circle around you looking for an opening, and the demon attacks!