Very fun and charming little game! The music was nice and the glowy art style is lovely, though I do wish the platforms were more visible and perhaps glowy as well, since they're crucial to the gameplay and also to show off their magical nature better.
The core mechanic is cool and works well, though I do think I'd enjoy it more if the game didn't start me out already on the run from an eldritch monstrosity. In the end, I didn't really bother using the weapon at all, and just placed platforms and ran to the right as fast as I could.
Overall, there might not have been much in terms of a "Metroidvania," which I presume was due to time constraints, but it definitely would have worked great as a boss fight in a bigger Metroidvania game!