Nice one :D
I was wondering when you'd get this out, and playing it again brought a smile to my face, even though it's 1am and my feet are sore and I have a headache. The controls are very simple and intuitive, but highly effective. The graphics were also fairly simple yet effective, which is probably good considering how much it lags when there are 200+ ninjas on screen. I love the dynamic background and the screams of the ninjas. It is very well programmed - I didn't find any glitches. My only complaint is that there are no highscore boards, so I can't tell if I'm good or bad.
Great game :)
P.s. Is this supposed to be an "evaluation version"?