Before going further, this review is spoiler-heavy. So be forewarned.
For a long time, I was not sure about this one. Prometheus was a mixed-bag, and I didn't like how much we saw of the alien in the trailer (although the above poster is SWEET).
In its favour, Alien Covenant is not Prometheus. The story is more straightforward, and scribes John Logan and Dante Harper even manage to clean up the pieces left over from the previous movie, especially David, Fassbender's ambiguous android.
In Prometheus, David's motives were confusing. In the sequel, we open on a flashback between a newly-minted David and his creator Weyland (Guy Pearce, reprising his role from Prometheus), in which the artificial man begins to see the weaknesses in his human 'father'.
In the present, David has turned on humanity. Having witnessed the flaws of his creators, the android sees the destruction of the human race, along with the god-like Engineers (previously known as the space jockeys) that birthed them, as his ultimate purpose. To that end, he has bidden his time, using the space jockeys' technology to engineer his own creation, an organism whose sole purpose is to kill all living things.
When the movie focuses on David, Alien Covenant is a joy. Both Frankenstein and Monster, his creation of the Alien is the most terrifying and well-realised aspect of the film. But when it does not, which is most of the movie, Alien Covenant is stuck in neutral.
The story is fairly rote, and the characters, while better realised than Prometheus, are never really fleshed out. For one thing, there are too many -- most of them solely there to create a body count.
But the biggest problem with Alien Covenant is the existence of Prometheus. For try as it might, this movie is a sequel to it and therefore is indebted to the confusing, muddled mythology that that movie created.
David's arc, from innocent servant to corrupt overlord, is a fine one. But it requires a knowledge of the previous film which -- going off memory -- did not lay the groundwork for that arc in the first place. So David's story is a retcon, and therefore the movie has to distort and bend itself to accommodate this backstory. So while it gets parts of this story right (such as Noomi Rapace's fate), other parts still carry the inconsistency of its prequel (the origins of the Engineers remain baffling).
The combination of the two strands also raises a logical inconsistency. The Engineers have created an airborne pathogen which infects and demolishes living organisms. Pretty insidious and (based off its use in the film) completely effective. So why does David need to create the Alien in the first place? Hubris? Maybe, but the Engineers' weapon ends up as the far more terrifying of the movie's alien antagonists.
Years ago I read a book about the making of the Alien movies. It was fascinating to see the ideas that did not make the cut: an alien temple in the shape of a crouching man, an alien that looked like a squid; a chest-burster that resembled a skinned turkey. One of the problems with Prometheus was that it felt like Ridley Scott had taken all those old, discarded ideas and put them in a movie. Whereas Alien felt unique and spare, Prometheus felt hackneyed and old-fashioned -- trying to explain everything that was unique and frightening about the original (the space jockeys; the alien's origins).
There is less of that gobbledegook here, but - aside from the airborne virus - the movie's new creature, the 'neomorph' comes across as a fairly bland knockoff of HR Giger's original design. It also winds up looking like a plucked turkey, but I'll give Scott the benefit of the doubt that this was not intended as a homage to the original chest-burster design.
Sadly, Scott's interest in the new toys means he deserts the movie's real selling point. The alien, when it arrives, is a tad underwhelming. A CG creation, Scott shows it in a variety of wide shots that dispel the creature's menace. In the first two Alien movies, part of the terror came from our inability to get a good lock on what the xenomorph looked like. Here, it is all-but strolling through scenes.
This review is starting to sound like a pan. Back to the good. Waterson's role is undercooked, but she is a solid lead. Danny McBride is also effective as the Covenant's blue-collar pilot.
Of the human roles, Billy Crudup has the most interesting character as the crew's captain Oram. Forced into the role when the original captain is killed during the incident that cripples the ship, he is a man of faith without the stomach or instincts for leadership. His humanity and weakness make him feel like the most relatable character of the cast.
Ultimately, while it is a far cleaner movie than the over-ambitious and inconsistent Prometheus, Alien Covenant suffers from the intertextual imperatives of its story, which prevent it from standing alone as a simple thrill ride. Check it out for the atmosphere, Fassbender's performance as David, and a deliciously bleak ending.