As a big Crypt of the Necrodancer fan, I love seeing this idea adapted to another genre! I think that it works very well with bullet-hell-like setup. Planning movements to escape damage zones and ghosts (knowing that I have only as much time as the beat gives me was really fun!
If you're planning on continuing this project, I'd consider unifying characters and backgrounds artstyle (I'd love to see this cute witch in pixel!!!) and working on diversifying game elements which block you from the decorative ones (in level 2, I've mistaken one for another a few times). Adding some beat-meter or consequences for being off-beat also could be neat - I had a feeling I was off beat a few times, but there was no game element which'd prove it to me ;)))
All in all, good job! The game is fun, music is enjoyable to listen to and I adore the lil jumps and tilts our main character does. Looks like dancing!