Way of the Samurai 2 isn't as good as the original, although it's much bigger. The problem is that if you don't do things exactly the right way you won't get a very interesting story going and you'll miss everything. In part 1 no matter what you do you'd have a story going, in 2 it's very easy to wander around aimlessly until the time runs up and then the game just ends.
I don't think it's completely ruined. If you liked the original it's mostly more of the same. It'll also really help if you look at a FAQ to understand how to get all the story branches going.