Enjoyable game!
I think it's quite hard to add something new to the formula of these kind of games but your idea of augmenting your spells or abilities is pretty cool. It could be a bit more intuitive like letting me choose which spell or ability gets augmented, but I really like the idea and what you could do with it if the enemies had resistances or special shield so would need to tinker around to find a working set of skills/abilities and augmentations.
The art style is pretty nice but it needs more polishing and feedback, the general direction thought is pretty nice.
Some parts of the music (the heavy ones) were also pretty fitting. Some sound effects would be nice.
Overall pretty enjoyable. Great job!