The best part about this game is the spells, they have really good sound effects and a nice punch to them, I think they have too much cooldown. An upgrade progression system for the spells would go really well too, unfortunatelly the graphics are lackcing but they are good at comunicating "flavor" to the enemies. As for level design, the arena could be smaller and the enemies could be faster, as it makes movement more needed and gameplay interesting overrall. Nice job!