I watched this again for the second time last night. I've already reviewed it on another forum, so I'm just gonna copy that over to here. Apologies if it repeats points already made but these are my thoughts:
I was massively disappointed by this in the cinema and was hoping to enjoy it a lot more second time around, but if anything I enjoyed it even less.
It's one of those infuriating movies where it feels like so much effort was put into the look of the thing, almost none was left for the script and characters. There are so many stupid moments that exist just to facilitate events, or confusing plot twists that seem to be included just so they could say they had some. For example, why are expert scientists brazenly petting unknown alien lifeforms that clearly aren't in the best of moods? And just what exactly did revealing Vickers was Weyland's daughter add to the film? Most of all, why are Vickers and Shaw running away from a towering object about to fall on them, when they could run off to the side and escape its path completely? So many moments just leave you thinking, "Why?!" and it totally undermines a film that clearly thinks so highly of itself.
What's more, unlike the Alien films, all of which had at least some interesting/entertaining characters, virtually every single individual in Prometheus is painfully bland. The only real exceptions are the characters who are elevated not by the script they're reading from, but by the fact that the person playing them either has serious natural charisma (Idris Elba as Janek) or hits their performance out of the park (Michael Fassbender as David). Everyone else was either a non-entity or trying painfully hard to make us remember/care about them. Fifield was especially bad as 'angry man'. Practically every line of dialogue he had was cringe-worthy to listen to.
Such a disappointment.