A clever and fun combination of genres with catchy tunes! I could easily see this being workshopped into a full release title. The theme interpretation is great, both on basic cliche and taking such an iconic game style and doing something fun with it. I liked the ridiculous story premise, too.
Some of the beats-attacks didn't sync quite right for me, though the on-screen circles were always correct. That may be Unity's wobbly in-browser functionality; I wasn't using headphones at all. A little bit of variation in the enemy sprites, even a simple recolor, would have added some spice, too.
Overall a fun time!