Nice game, only got glitch out via the table.
I think that it's hard to kill all the skeletons without running out of mana. It's part of the game but maybe it's to much skeletons or your mana empties too quick.
For a jam game it doesn't matter, The idea is nice and if you want to expand on the game you this is an option. There are probably other ways to improve ;)
in general I liked it! :D