Pretty nice puzzle game I'd say. I love the visuals and the mechanics are fun and relatively intuitive, though at first I wasn't sure how to kill the demons without any bullets.
as an improvement I'd appreciate a checkpoint system (maybe there is one in later levels, but I couldn't win level 1 and gave up after the lava drop... that was cheap man...)
Also is there supposed to be sound? I don't hear any sound or music on Firefox/Linux :c
Other than that, I really liked this. Kinda super meat-boy-like, I can imagine playing this from time to time if it was finished :)
PS: The gore/gibs explosion was a nice effect!