Touhou fan here!
I did a playthrough on this game, and while not bad at all, needs some improvement.
1) No visible hitbox or hitbox. This is a big factor in touhou games, and while this game uses a pixel like design, a hitbox or a location of the hitbox should be shown.
2) No change in bullet patterns. Score multiplier changes along with lives, but there is no difference in bullet patterns.
3) No slow button. Speed matters. It can be the difference between surviving and losing a life. If you stop shooting to dodge bullets, the time taken to kill the boss is far, far longer.
4) Unable to focus shots. Unable to increase bullet powers slows game progress down.
There were some things i did like about the game, that being the soundtrack, which was very well done! The art was impressive, especially the danmaku patterns, and is quite good for a fangame. Personally i would suggest adding dialog boxes, or spellcard effects (E.G Marisa's master spark shoots a rainbow) Or more stages! Pre-stage bosses, while not mandatory, are welcome too :)