I disagree with all of the music choices, hands down. Using rock/metal for a Samurai assassin in an odder setting... Don't know, but the soundtrack I think could have been a little more thought out. Also, why the heck was he green?
The animation was on and off for me. Sometimes really good (like the sequence in first few frames - very impressive) or really odd and ill-constructed. Not bad, just required some better planning I think.