A fun and interesting mechanic! I also like the music! The concept is executed wonderfully and the game is fun to play!
The only thing I wanted to see was more game juice, more particles, camera shake and the other good stuff, that would definitely make the game a lot more fun to play! I also think that the waves should be shorter, I had to wait a long time to advance to the next wave, and the game is kind of boring in the first wave, and it only gets more interesting after we advance more waves and new enemies start spawning
Overall an awesome entry to the jam! Great job!