I enjoyed the mechanics, although the game needs a bit more balancing. I'd have the player be a bit faster, as chasing down enemies is too frustrating. I'd space out the spawn rate or have them endure less hits. I got overwhelmed really quick and I didn't even manage to kill the first mob.
I think it would be a great addition to allow clicking on the spells, as need a hand on the mouse for clicking corpses makes it hard to get t the spell slots with the other hand busy on moving and attacking.
Also whenever I died mobs just kept attacking me and nothing happened. I'm not sure if I was doing something wrong.
I think this has great potential to be a really fun game. Nice job!