This is a really hard one. Took me about 2 hours to get into it. The characters are great, the actors do a fine job (better than the prosthetics department anyway).
I guess this movie is kinda like life. It runs much longer than you would expect (and perhaps it needs to) and nothing adds up till the ending comes near. But then you wonder whether you missed something in the beginning that would have made the journey more complete, realizing or rather suspecting, just now that the credits run, that there was so much in there that might just have made sense if you hadn’t missed or already forgotten about it. There is some depth in there after all.

Or in other words: Watching the film closely you can’t be blamed for not seeing the vision that might be behind it.