Wow, what a coincidence. I just finished the game yesterday, myself. I told myself I had to beat it before I started playing Assassins Creed.
I have never wanted to cry more in my entire life. That is how I felt while playing the game. It was soooooooo damn difficult. I kept wanting to abandon the way of the ninja, but I didn't, I kept at it, and now I can play AC.
P.S. Anybody else find Rachel's jiggling breasts hypnotizing, LOL.