Really incredible game! The soundtrack and visuals are phenomenal, and it has some of the best difficulty scaling I've seen so far (probably a weird thing to comment on, but getting difficulty right in game jams is exceptionally difficult, and you nailed it here).
I also like the turn based combat a lot! It seemed a bit weird at first but it fixes a fundamental issue that a lot of bullet hells have, where attacking doesn't mean anything but holding the shoot button until the boss dies. Here it actually matters, which is awesome.
The only things I'll comment on is that a boss health bar would be nice (not all the time, maybe just something that appears during the player's attack animation), since at times it felt like I had no idea how much progress I was making. And that while the cat and boss look great in isolation, there were enough stylistic differences between them that it slightly hurt the overall visual cohesion of the game (not much though, just enough that it's worth mentioning). Finally, I'm not really sure how this fits the theme, but that's hardly an issue with the game itself.
Also I played the web version and the text worked fine for me. Maybe it's a browser specific issue?