I think there isn't much to the Noah story, so the writers added a few things, like talking rocks, a magical grandfather (and pregnancy), a pointless king (at least in the latter part of the movie), and a God that sucks at communication. If I was tasked with creating a basic story-line, I would have had the Noah family actually go find those animals themselves instead of them magically be brought onto the ship. In addition, I wouldn't do the lazy thing where they are all put to sleep.
I was surprised (and disappointed) that the movie was directed by the great Darren Aronofsky, who gave up Pi and Requiem For A Dream. There is nothing interesting/provocative enough to deserve such a skillful person. The visual design may be interesting, but not by much. It is dark and desolate, which is typical of his movies, but it's too bland a story. It's epic, yes, but it's also based on one of the most nonsensical of all stories in the Bible.