Instead of having a blank element circle at the start, would be nice with some "this element is locked" icons
The reflected lights on the health and mana bars look kinda weird and I thought they were little bars of their own.
I can't figure out what the green element is supposed to be. Plants? Some kind of force magic?
In any case, fun little game. Fun looking art style for how basic it is.
My only real gripe is that having limited mana because of limited enemies means you could very easily waste all your mana and get stuck, unable to progress. This disincentivizes actually using magic to fight enemies in a game about combining different types of magic in fun ways to fight enemies. Giving the player a teeny bit of mana regen would fix this.