Amazing work! This feels like a full game! I loved the cutscenes, writing, and game mechanic. My only complaint is that the levels themselves just needed more playtesting (e.g, many levels are more or less impossible for multiple attempts only because I don't know what will be coming... a Celeste-style "viewfinder" would be an easy fix). For a game jam, that's totally expected though.
One personal preference thing: you created a very cool spellcast mechanic, but then limit it to a square grid. Given the nature of the spells, an Okami-like "draw a circle" could have been more evocative!
Huge thanks for adding the accessibility options. I would not have been able to see the ending without them :) Even with both on, the boss was hard for me!