I loved the art for this game, and everything felt really good to do. Having the spells change so that I have to consistently change my aim in order to make sure I hit my shots was a good design choice, especially because not all enemies die to all types.
I found the game extremely difficult though. Once I got to the levels where the third enemy showed up I stopped playing. Part of the difficulty is that I am not looking at what spell I am casting, I'm looking at the enemies, and I would get tripped up on where to aim. It's hard to visualize each trajectory, a lot of times I got a good one through luck.
Good job though!