The prequel that isn't a prequel that really is a prequel to Alien. If you're watching this movie as a fan of the 1979 movie with Sigourney Weaver and looking for answers, I'm afraid you're going to be sorely disappointed. The movie's screenplay is co-written by Damon Lindelof, one of the writers/creators of the hit TV series, Lost. So before you even step in to the cinema, you should be prepared to come out with more questions than answers.
There are certainly many Easter Eggs that pay homage to the 1979 film, but to call this an official prequel is a little bit of a misnomer. What it is, is the introduction for a new series based upon the Alien creature. The curious thing is, the way that this story is written, the Alien creature doesn't even have to be involved as this particular story moves forward, which makes it pretty interesting.
The cinematography and set design in Prometheus was astounding; as was the performance of Michael Fassbender. The story moves along with thrills and scares and all the things you find in a Sci-Fi Thriller/Horror film. But Prometheus tries too hard to do too much which just simply leaves too many holes for me to give it a better grade. Without including spoilers to this movie, the trials and tribulations of Noomi Rapace's character is so far fetched that it was no longer believable.
While I could point out all the plot holes and things that really don't make a lot of sense, I would be giving too much away. But given all the issues with this movie, why is it still a B-? There's enough there to give you a thrill ride. There are enough questions left unanswered for there to be a viable sequel. And there is certainly enough there to make you squirm in your seats and make you wonder if space exploration might not be such a great idea.
Casual fans of the movie might not want to stay until the end of the credits, but for y'all die hard fans, there is something there that you might want to stick around for. But don't blame me if you do. haha.
Here's an interesting TED talk video related to the movie that's rather interesting: