First, Touhou yay!
Second, disclaimer, I didn't manage to get anybody else to play this with and I'm pretty much a casual noob at fighting games.
Now graphics and sound pretty notch, there's even a trailer and several custom marketing pics. Gameplay felt nice from what could be experienced fighting an opponent that can't fight back, although again I'm a fighting game noob so take that with a grain of salt.
Still it's definitely missing some way for a solo player to play. Not sure how hard it is to make a fighting game AI, but something, anything, would be better than nothing in that department.
Ditto for other characters. From the trailer and pics, there seem to be other character models already done and at least partially animated. Even if they're not as polished or have bugs, it would probably be good to add one or two others to spice things up. Not even need of making a custom moveset, just recycle Reimu's moves with some changed speed/damage values in a pinch. Even big-name fighting franchises like Super Smash Bros do it after all. Point out it's placeholders and eventually every character would get their original moveset, IMHO people checking this out won't mind.
All around, plenty of potential here, great work!