Now don't get me wrong, they basically stick to the story. I mean, they did a much better job than, say, Eragon. (yeck) I'm just warning you that some things are a little more fleshed out, some things are left out, and some things are completely new. But it's still a really good movie. I'll gladly watch it again!
What kinda freaked me out was the violence - or lack thereof. I mean, it's a war movie. It has battles. People get killed left and right - but somehow most of it you don't see. For example, a man is beheaded right on screen, but you don't see the decapitation. I still haven't figured that one out.
So all in all I liked it. I don't think I'll add it to my top 5 movies, but it was fun, had some good take-away moments, and had the most adorable mouse ever.
Oh yeah - and on a final note: The Telemarines are Spaniards. It's blatantly obvious, so don't think they're supposed to be from the desert or something. They're not. Read Don Quixote.