I don't know who wrote this, it was brought to my attention via a friend, but below is the best summary of PROMETHEUS I've read. [I have removed one word, describing Erich von Daniken, in case of libel.]
"The opening was problematic, and I really hated the two main characters and their smug creationist views that go almost totally unchallenged by an entire crew of top scientists, but the good stuff was more than enough to outweigh the bad. The approach to the planet, the setup of the mission, and the gradual exploration and discovery of the alien world and abandoned structures was incredibly atmospheric; I was completely absorbed by the beautiful, dense, scary world the film was setting up.
And then there was the bit where they opened the space jockey skull to reveal that it was a humanoid in a suit, and my heart sank. For the first hour, I'd been watching what felt like a proper SF film - a flawed one, admittedly, with scientists that acted nothing like scientists, who cracked open their spacesuits on an alien world on a whim as if they're the biggest fucking idiots imaginable, but an SF film nonetheless, one that's about discovery and awe rather than slaughter and action. That bit with the Engineer skull confirmed all my worst fears about the film - that it was going to retrospectively take all the mystery of Alien's unspoken backstory, and render it prosaic and dully predictable. The space jockey in Alien was one of the great moments of SF history, a neat, horrifying, piece of implied backstory that's been turned into a tedious rehash of near-forgotten Erich von Daniken.
That didn't necessarily ruin the film - it could easily have survived that revelation, if it had sustained the intrigue of the story and the setting. But that bit signaled the beginning of the end of the script making any sense at all - the clear mystery and story of the start gradually unravelled, and got muddier and more confused as the film went on. Alien was so successful partly because it had a simple, compelling, premise, and a pure, terrifying concept - the creature's lifecycle is simple, disgusting, and convincingly deadly, and the film executed this vision perfectly.
Prometheus has an engaging premise, but the concepts behind it are so confusing as to be completely mind-fucking. None of it makes any sense; there’s some kind of engineered contagion on the planet that oozes out of cylindrical objects. It makes Engineers’ heads blow up; when ingested by humans it makes little worm-like things come out of your eyes and makes your skin go black, and when sexually transmitted, it makes a scary octopus-like thing grow inside its host which then hatches out, grows to the size of a small car, and then impregnates another host which in turn gives birth to a weird thing a bit like a classic alien but not quite and the cylinder goo also turns different little maggot-like things in the hive into terrifyingly phallic serpent things that go down people’s throats and kill them and have acid for blood and when people are sprayed with the acid they turn into homicidal zombies with stealth powers and super strength.
I mean, what the fuck. Compare that to the purity of the original alien; it’s a complete mess. The film as a whole is as much of a mess as the concepts behind it - people have mentioned all of this already, but things just happen for no reason. Stringer Bell plays the accordion, has sex with Charlize Theron, and then suddenly appears in someone’s room to spiel off a load of exposition he can’t possibly know (“this is an installation full of WMD!”) (I suspect this scene was chucked in at the last minute to tie the plot together); Noomi Rapace is stitched up by the Company, fights her way free, undergoes a terrifying surgical ordeal, is literally stitched up again, and then doesn’t mention this to anyone and agrees to go on a little jolly with all the evil Company people to the planet’s surface. Michael Fassbender activates a spaceship with a magic flute, which turns out to be crewed by a mad wrestler. Charlize Theron kills a man with a flamethrower, with no apparent consequences. It’s just fucked, there’s no other word for it.
You could argue that the film at least tries to raise more questions than it answers, and generates intrigue in its world, but these aren’t so much questions to be pondered as clumsily set up hooks for a new franchise. Prometheus provides boring and prosaic answers to “mysteries” that were never supposed to be solved, spends a lot of time setting up new narrative mysteries, and then seems to deliberately withhold answers from the audience to spoilbind them to the next couple of films in the series. It seems contrived, cheap, and slightly contemptuous of its audience.
So yeah, a beautiful and well-intentioned film, ruined by idiocy and a lack of focus."