I got a score of 1712!
I loved this concept, and almost made something very similar for my entry but shifted gears at the last minute.
I love that all the sound effects were musical instruments, and that the hit sound was a hi-hat.
I would have loved to see the player fight with more instruments instead of just the kick drum. Additionally to upgrading the shape of the player, maybe there could be upgrades that add new types of “weapons”. For example, it fires a small “bullet” at each edge connection and plays a hi-hat sound when it does so (on the up beats). Or maybe you have a second loop going around the shape that plays a snare drum and launches a different kind of attack.
Also, auto fire should be the default setting, there’s no reason to let go of the space bar.
Amazing game, overall. Congrats!