Well, that was... one of the most challenging fangames I've ever played. Not in a bad sense, fortunately, but wow the last level was a hair-pulling(but satisfying) experience.
Kogasa is my favourite Touhou character so admittedly I am quite biased for this one, but I did enjoy it despite the absolute frustration it gave me. The gameplay was interesting and unique, and I like how the fact that you can block from all 4 directions can make for some fun strategies to get around each section. Visuals and audio are also of a high quality.
The biggest suggestion I have is to add checkpoints, or make an "Easy" difficulty that has them and a "Normal" difficulty that doesn't. The last level is... really long and hard and was the one especially in need of them.
Good work on the game, and I hope you make more cool Touhou content in the future.