There is a lot of good that I like about this but in order for it to become much better theres a few changes I would make
Since this game is a lot like Mad Rat Dead, I think a downward slam ability would help the flow a lot more, allowing the player to string together long strings of keeping with the rhythm instead of jumping in place when they have to wait for something. This would also improve the general flow of the platforming.
Additionally, the crippling stun that the player gets when they miss a beat doesn't feel like a proper punishment, it feels unfair to punish the player so harshly for doing something that is fairly easy to do.
The last thing is that the music needs a change. The music itself isn't bad at all but what makes similar games like Mad Rat Dead work so well is that the rythm of the music is very well defined, and keeping to that rhythm feels like an extension of the song.
All in all a nice proof of concept that has enough differences to stand on its own, but is also quiet clunky and frustrating when put into practice.