Cool concept, the combat system is very unique. I really like the art style for the game as well.
For the first 4 levels there didn't feel like much choice and no way to actually lose. I would suggest something like unlocking 2 things at the end of each level instead of 1 maybe, or something to allow for more choice early on.
On a side note I also ran into a few bugs that forced me to restart a few times (these things happen in game jams a lot), for 1 if you accidentally select a spell that doesn't lead any where then it could freeze and also randomly at level 2 sometimes it would freeze up completely as well and I would have to refresh the browser.