Eric Ericksons account of the movie tells all. It almost sounds like a comedy it’s so out there.
....
Noah and family rush past a mountain of skulls and are attacked by giant rock monsters. The rock monsters hate people. Turns out they are fallen angles who decided to take care of Adam and Eve once the “Creator” cast them out of Eden. To punish them, the Creator covers them in lava making them rock monsters. They protected Cain’s folks until the people turned on them. Only Methuselah with his magical powers and flaming sword could protect the rock monsters from men. The rock monsters are rock like Ents, but behave like the green space aliens in Toy Story. They always look up and sing “the Creator” instead of “the Claw”
http://www.redstate.com/2014/03/27/darren-aronofskys-noah/
I like watching science fiction movies, too - and that’s what this sounds like. However, no one should confuse this movie with the account that God gives us in the Bible.