In this game, you defend your newly acquired power with mana that becomes dangerous in great concentration. There's Unusable, Usable, and unsafe versions of each spell.
There's a learning curve to the rhythm of the spells, but merely hitting them in their time slot is not a good strategy. You need to figure out what spells you want to overload and what spells you want to be safe with. For me, Wind and Ice were my Overload options while Fire and Earth were things I wanted to use the safe version of.
Ultimately, I could not go very far into the game. Brain is still recovering from a previous mind bending game in the jam, and that makes for an unfair evaluation. Make no mistake, your game is rather engaging, just that it's also taxing.
Overall, I see this one as a contender. Usually, I have more to say, but my headache isn't going away, but I think you'll be high up there!