A fun time-waster.
Definately a fun game to play. While the stage portions feels a little short, they're replayable, and survival mode helps too, though it seems to ramp up a little fast.
My only complaint is that Holy's "spam" spell, Smite, does not cause splash damage to enemies nearby the target, unlike Fireball and Frostbolt. While you can clear the stages using all Holy spells, this puts pure Holy at a pretty big disadvantage in Survival mode, especially since it lacks a huge AoE spell as well.
Overall though, it's a good game, and has a lot that could be built on if you decide to make a sequel (please do!).