Very original idea and very polished game, the game feel is fantastic. The gameplay needs some tweaking, because in the end I just played looking at the board with the spells being extra effects I gained for doing nothing. The only timed I used them willingly was when my knight died and I could revive him with a spell. By just focusing on making the mage follow the easiest path I was able to reach floor 90 on my first try without having to make any interesting decisions. Still, I understand that with the time limitations it's impossible to properly tune the gameplay so much.
Overall a very good game, one of the most creative ideas and I see a lot of potential for this if you develop it further: You could even add more unlockable characters with different spells and special mechanics. Great job!