I really want to like this game because it's very touhou-coded but the forced full screen, mouse issues and no control explanations outside a paragraph on the page make it really hard to appreciate.
I played until the boss, the patterns are certainly interesting, it's too bad that slowing down does not show the player's hitbox.
Sadly I couldn't really engage with the other mechanics because remembering all the buttons is too overwhelming without a tutorial or on-screen prompts of some kind.
Also I think the boss music is way louder than the stage music, they should be the same volume for an enjoyable experience.