Put aside your expectations that it will be an "Alien" film.

Rating: 8/10 (4 October 2012)

I've had a tumultuous ride with "Prometheus." When it was initially announced, as Alien 5, with Tony Scott's son-in-law directing (he's now making a Samurai movie with Keanu Reeves and been kicked out of the editing room by the studio because it's gone far over-budget, btw), I was cautiously optimistic. When Ridley took it over, and it was re-announced as a prequel, I was more optimistic.
When they began to basically hint that they were retroactively altering the 'Space Jockey' creatures from Alien, I grew a bit worried. One of my biggest delights with Alien, as a child, was the weird Space Jockey creature they stumble across, and you can just tell from the way it was filmed that it was meant to be another alien species that was killed off by the titular alien species.
What Ridley Scott decided to do, however, was (and I don't think this is even a spoiler, by this point, but stop reading now if you want to know nothing about Prometheus) retroactively claim that the Space Jockey wasn't actually just an alien but, rather, an exoskeleton suit of sorts, a kind of bio-mechanical grafted suit, and that the alien inside the suit is actually...the ancestors of humankind.
So immediately you get the idea that Ridley isn't just making an Alien prequel. This is a movie with bigger themes and ideas and it only truly connects to Alien in a few ways, and minor ones at that.
I think, after seeing the film and realizing how little it connects to Alien, the retroactive altering of the Space Jockey didn't bother me as much as I expected it to. Will I re-watch Alien from now on and be convinced that the thing in the chair is a human engineer who looks like us? Nah. But within its own universe, Prometheus works well, and the story it has to tell is engaging.
This may not be what most people expected, but if you can meet the film on its own terms, it's quite a ride. And while the characters do indeed act quite stupidly at times, Michael Fassbender is amazing as David. He deserves an Oscar nomination.