The story, unfortunately, is another matter entirely. Inconsistent characters, ideas that go nowhere, and senseless decisions abound. The film evokes a brooding mood, a wonderful air of menace, and hints at incredible secrets, but fails to deliver.
Written by Lost writer Damon Lindelof, Prometheus raises lots of questions. Sadly there isn't an answer in sight. Given that Lindelof seems to randomly pull ideas out of a hat, examining Prometheus for meaning may be an exercise in futility.
But let's assume there's method to his ever inventive madness here, and take stock of what we do know:
A buff bald alien dude drinks bioweapon spiked Cool-Aid and gets a wicked case of disintegrating heartburn. DNA mixes with water, simmers for a few eons, and out we pop.
Now, what evolves out of contact with the bio-goo (whether it be giant arm breaking worms, bulb headed zombies, us, or crazy ass starfish fetuses) varies. The bio-goo weapon is adaptable. Different result every time.
So humanity itself, the product of bio-goo mixed with Engineer, is essentially a living weapon. Just like the xenomorph is a living weapons system, except the xeno mixes in one more element (human DNA, provided by Rapace).
But why then would the aliens have happy, non-genocidal finger paint parties on temple tops with our distant ancestors? Everything was sympatico until two thousand years ago when they decided to exterminate humanity. Unfortunately, the fate they planned for us consumed them instead.
Aaaand what happened two thousand years ago, on earth? Cue repeated, ponderous references to crosses, Christmas, and Christianity. It seems that when humanity decided to go all monotheistic and Praise Jesus two thousand years ago, the aliens decided we had to be stomped out.
This raises a few questions: is it faith the aliens object to? Or was Jesus himself a ripped alien prophet that we rudely nailed to a cross?
Perhaps it was all a dream. Or it's purgatory and they're all dead and the Engineers are angels. Or she went to Recall or she's really in a mental institution and the whole thing is just her way of dealing with being incarcerated and plied with narcotics. Or maybe it's a fantasy program running while she's on her way to Mars.
Maybe she's really a delusional monkey tripping on bad bananas.
The sequel(s) may deliver satisfaction, which would be wonderful, but I'm not going to hold my breath.