Watched it last night.
I'm not a huge Alien geek since I've only seen the first one (but do love it), so I wouldn't put this down to that... but I was quite disappointed.
Visually, it's stunning. Even superior to Avatar. However, like Avatar, it was quite thin on plot.
I can't quite remember character names (since most were left off-screen for much of the film apart from David (Fassbender) and Elizabeth (Rapace)), but those two were by far the best actors. Idris Elba and Charlize Theron played well too, there was really nothing at fault with the acting.
I didn't realise Guy Pearce until I found out he was the old dude.
I spent a lot of the film hiding behind my hands since the tension music was sort-of overused and a lot of the time resulted in nothing, but a lot of the gore and attacks were pretty terrifying.
Spoiler:
Fyfefield's reanimated body attacking most of the nobodies in the holding bay
But one thing I didn't understand was the Scottish woman. Was she an android? Since she was helping Weyland and David to try and contact the lifeforms after Elizabeth's boyfriend bit the dust... it's like in the film's quest to "answer life's unanswered questions" it just left the audience with even more
Oh and the birth operation scene was fantastic.
Overall it's a visually breathtaking and action-packed film but is ultimately let down by direction and lack of plot :/