I beat the game :D
Overall I found this game to be amazing and strategic. The premise of the game wasn't too hard to grasp, it just took a bit of reading of the description to understand. The artstyle was awesome and the audio was fitting, alongside the music.
The progression of the game was also surprisingly fluent compared to other tower defense games, although at times I found it very easy, but that's probably because of some of the tactics I have found effective in beating the game, such as using freeze turrets early on in the game to increase the effectiveness of splash turret damage (since slower enemies end up grouping together more closely), and also that using earth magic is very effective for crowds.
If that description on itchio didn't exist, it would have probably have taken me far longer to understand the game mechanics, therefore to improve, I'd recommend having an in-game tutorial instead of a story, or both, if you can manage that!
Lastly, having some game juice may be nice for your game. The art is amazingly well made, but the effects of the magic itself aren't felt as much without things such as mild screen shakes, flashes when enemies get hit, damage counters, more shaking effects, and other fun little effects to maximize player feedback. In a game about magic, the more game juice the better! :D
Overall, I found this to be a fantastic game, well done!