"So anyway, I started blasting" <- This is what Touhou is all about, lol. Great description.
Really cool game. I've wanted to play this ever since I heard about it, so thanks for making a build.
Regarding the game; audio, visuals, and concept are all top-notch. The game is not particularly difficult, and only requires some patience from the player, which is both a plus and a minus in my book. Other lightgun games usually have DPS checks here and there, to punish defensive play and low accuracy. I don't necessarilly think the game needs to be more difficult to finish (it's good if jam games are playable for people with all kinds of skills), but it would be nice if the score system took accuracy and time into account. A hi-score feature would also be nice, for added replayability.
I'm super impressed that you've managed to implement multiplayer (online and offline?). I'll try to find someone to play with.