Hello! Nice idea, and here is a quick bug-report/feedback: flame elemental doesn't work, you should decrease a little the distance you are moved when you get hit (can create hit chains and lock you against a wall), reduce the opening time for chests.
Then, here are a couple of ideas for the game itself that I'd love to see implemented - but they are by no means necessary, just a bit of creative feedback for you :D
I'd love to see a quest mechanic, or a treasure map, as opposed to random chests placement. I felt as if I was roaming aimlessly, and while that's kinda standard for reverse bullet-hell roguelikes, implementing a different mechanic would make your game stand out!
I'd also enjoy seeing different basic attacks based on the magic school, and the possibility of obtaining new exclusive spells through the aforementioned quest mechanism (along with chests, of course!)