Lots of potential here.
The initial feeling was one of sweet, sweet nostalgia (I enjoyed mega-manning my way around the intro level very much). Then comes the sudden meaty boss fight. -Took me a couple of goes. Wasn't sure if I was doing it right when the monsters appeared to spawn randomly. Also the hit indication on the enemies seems to be different between the Shuriken and blade. Shuriken turned out to be the most effective way to tackle the big dudes on the ground, but I wasn't sure that was a winning strategy until it was over. (Maybe I just suck :D)
Also getting surrounded by baddies was the worst, but I got the hang of it eventually. Is there away to have Azumi stomp on smaller enemies when landing right on them? SQUISH! That's be awesome.
I love the art direction and music! Though I hope to see more animation. It's a got a lot of potential for some cool death animations ala Metal Slug. Also Azumi has only one arm? Will she ever get a wicked Big Boss style prosthetic? That'd be cool!
I'd better stop. This looks sweet, guys!