Honestly,
...This whole ninja/samurai THING has been re-hashed so many times, there's no real reason to criticize it. Instead, I suggest you put down your anime for a few seconds and pick up an American animation book. One that talks about timing and weight and PROPORTION AND CONSISTENCY, Oh god yes, two very important things to remember for successful animation. The reason I'm putting it this way, is because I saw this on the frontpage, and I think that you have a lot of potential with your animation. I say do some character studies, a lot of figure drawing, and work on simple animations like balls bouncing and whatnot. Focus mostly on the animation, and drawing, and less on camera angles and 'being cool'.
Keep workin', I see good things coming your way.
Aaaand that's my monthly critique.