The story is probably too complicated for a movie, which is why it is ridiculously dense. But I'm sure the same can be said for the Harry Potter films.
The issue I have is mostly with the writing. It is too minimal and thin, and by that I mean that there are parts that could and should be used for exposition, that either aren't and so it feels like something is missing, or they are used poorly and only reveal certain information, and do so in a very clumsy manner. It feels unpolished and not as concise as it could be.
Additionally, the structure of the film is very uneven. Long, uneventful and unfulfilling scenes are followed by very short scenes, densely packed with loads of complicated information. Not only that, but the dense scenes often featured a character who only appears briefly and then leaves you wondering what the hell just happened (the first appearance of Eva Green, for example, in which she comes, gives a shitload of backstory and a little insight into the future, and then leaves and we don't see her for another 45 minutes). It was difficult to follow along and highly inconsistent.
I do like the actors, for the most part. I wish there were a little more Daniel Craig, but that's for purely selfish reasons (damn, that man has the most amazing blue eyes). Eva Green was nice, too, and Sam Elliott might have been my favorite character overall. And while I liked that Freddie Highmore and Ian McKellen provided voices, it would have been awesome if they were actually in the film. Oh, and I feel it necessary to just mention Christopher Lee, and leave it at that.
It was an interesting story and I feel like the book would have been very good. But as a film, it is simply clumsy.
And now I really need the sequel because the whole second half, I was waiting for the big confrontation with Daniel Craig and then nothing. It just ended. Ummm...boo. At least Harry Potter resolves at the end of every book/movie (except possibly Deathly Hallows which is currently listed as having "Part I" and "Part II" on IMDb, with release dates a year apart. Boooooooo).
Alright. I think that was all. Or at least I'm close enough to having finished putting all of my thoughts in the post that I don't feel the need to complete it any further. Just call me "Leonardo."