I just saw the movie today. I liked it for what it was: mythic storytelling. Though it is most closely related to the careless (if not outright preposterous) accounts in Genesis, it departs from Genesis in significant ways. And these departures have dramatic effect because they create suspense: who lives and who dies? If you've read Genesis, you'll know; but this movie isn't following Genesis in all respects, is it?
The message of the movie seems to be that the Creator does not communicate plainly or directly with people, and so people feel they must find the Creator's wishes by less accurate means: dreams, interpretation of signs, that sort of thing.
And once they've convinced themselves that they know what the Creator wants, and though they cannot supply evidence backing up their knowledge to anyone else, they are prepared to discard their rationality and do monstrous injustices.
Now, certain friends of mine, who are members of a certain church, have had a certain hissy fit about this movie. They were absolutely convinced that the rock monsters were non-biblical. Yet I recognized these creatures right away as either the sons of God or the Nephilim. (The typical interpretation, but not the only one, is that the sons of God were supernatural beings that mated with human females to produce a race of giants, the Nephilim.) The Noah story starts in Chapter 6 of Genesis, and the first verses of Genesis 6 make mention of the sons of God and Nephilim (or "giants"). The Bible also mentions that the Nephilim lived after the Flood, suggesting that they somehow survived.