I gave it a B-. I enjoyed it well enough, but it simply didn't blow me away. I never really expected it to live up to the hype, so I was disappointed, but I did expect more from it. The film looks fantastic, the cast are mostly excellent and the production design is excellent. But the script really lets it down for me.
Far too many nods to Alien, it's almost a tickbox of the main points of the original movie. Guy Pearce was wasted. Noomi Rapace's character just didn't pull me in. They were clearly trying to recreate Ripley with her, and it just didn't work. Ironically, I found Charlize Theron's character more nuanced and a bit more interesting. Might have been interesting if they'd combined Rapace and Theron's characters into a single role. Fassbender was excellent, and I really liked Idris Elba's Captain.
I agree the trailers gave away way too much.