I sort of missed out on this when you first released the demo 'cuz my computer was utter shit, and ran it ridiculously slow, so I never got a chance to get into it.
Now that I've played it, I'd say this was incredibly fun, but it was sort of made a lot less enjoyable for me 'cuz it seemed to be riddled with bugs.
Movement is really nice and fluid, and the combat is great once you start understanding it. Still have no idea what I should do to beat the boss, but I'll get it eventually. I really love the presentation as well. Music was really cool, and I love the chubby little ninjas.
My problems are with the bugs. Sometimes when transitioning between rooms I suddenly find myself stuck in a wall somewhere far off. I can't hold the up key in between rooms, which makes climbing those tall shafts way more annoying than it should be, and when fighting the boss for the first time the level music never cut out and the boss music just played over it. When I died, the music still went on, even as the game went back to the title screen. Now, the music doesn't start at all, and every time I die I get an error:
action number 1
of Step Event
for object stopmusic:
Error in code at line 1:
if vol>1000 then vol-=100
at position 8: Cannot compare arguments.
Anyways, I was still able to overlook the bugs and enjoy the game immensely. You've got something really amazing here.
As for the XBLA question, yes, of course I would buy it. Whatever price you put up, really.