I enjoyed it but I think my expectations were too high so it only gets a C+.
On the plus side, Fassbender's David is fantastic and the movie's early scenes with him on the ship were nicely done. The sets and actors look great, and the concept is really cool.
However, I don't know if it's just that shoddy writing has become more acceptable in the last 25+ years or if I'm being hyper-critical but I was disappointed in the movie overall.
I watched Alien on TV the other night just to get myself in the mood and there really isn't much comparison in the quality of the storytelling (all Alien needs is a bit of CGI in the closing scene when the alien is blasted out the hatch and the movie would not date at all).
For me the story started to go downhill once the crew started to interact. They did a really poor job of establishing the characters early on, many of whom, for some inexplicable reason, had not even met before setting off...? Even at the end of the movie there were several characters running around who had done nothing more than deliver a few lines of dialogue. I genuinely believed that Charlie was Elizabeth's gay best friend rather than her lover until it became obvious, quite far into the movie, that this wasn't meant to be the case - there was very little chemistry there at all.
What jarred the most though was the lack of realism in the characters' behaviour. In Alien we were dealing with working class joe public; in Aliens we were dealing with boneheaded marines; in Alien 3 we were dealing with criminals but in this movie we were supposed to be dealing with scientists. Why then did they go charging in like idiots?
They didn't set up a lab on the planet to examine finds without risking contaminating the ship, they took helmets off without taking samples of the air for bacterial or viral analysis, we had a geologist who didn't even carry a samples case and a biologist who wasn't even carrying a basic testing kit. In one scene somebody asks why the water isn't frozen given the temperature - do they stop to take a sample to find out? No! Someone says, "Maybe it isn't water," and on they go, wading through this unknown substance without a care in the world.
They claim to have a quarantine procedure but given that their basic safety protocols are lacking, they would have had to quarantine the entire crew.
In short, their scientific method was shambolic and it really dragged me, almost weeping, out of what should have been a decent story.
The plot was a bit obvious compared to the first two Alien movies. I was mildly offended when one of the characters, despite having a serious injury, was performing physical, one might even say, acrobatic, activities with little more than the odd wince of pain. Given the larger cast, I would have much preferred it if they had taken a leaf out of Contagion's book to keep us on our toes with several leads, any of whom could die at any moment, sharing the burden of action hero among them.
Overall, I did enjoy it but it fell quite a way short of what I was hopng for. If Del Toro wants to make in the Mountains of Madness there is plenty of room left to do a better, more atmospheric job.