They're claiming that Prometheus isn't technically a prequel to Alien, despite the same universe and director. But that's not quite the truth. And that's not going to stop comparisons to Ridley Scott's 1979 sci-fi classic.
Set roughly a quarter-century before Ripley's fateful space run, Prometheus follows a crew of explorers (played by Noomi Rapace, Michael Fassbender, and Charlize Theron, among others) in search of nothing less than the origin of mankind on Earth. What they discover is a monumental testament to grand set design and spectacular CGI … and a planet oozing with monsters directly related to the ones that destroyed the Nostromo.
Bigger issues loom – faith, creationism – but the movie is smart and savvy with its scares, even if it doesn't pack the visceral punch of the first two terrific parts of the saga.
Much of this has been covered before – the slow, scientific build-up, the alien-infested landscape, the robot crew member – but the mythos that Scott and the writers construct here open up a new world of possibilities. --Michael Gallucci