Just a quick, off the cuff review (and I'll try not to give away the end). If you've seen one alien movie, you've probably gotten the gist of this one. Or, rather, I should say, if you've seen any recent sci-fi movie, you'll get the gist of this one. The Aliens franschise over the years has seemed to be a reflection of the times.
The whole series began as sci-fi/horror. The first movie basically introduced the horror concept of aliens bursting out of one's chest, etc. Back in the day it might've been compared to the movie "The Thing" or "Bodysnatchers". The second movie, which was the first one I saw, with Sigourney Weaver, and the late Bill Paxton, is the one where the space marines engaged in some extreme pest control measures. In the end they "nuked the site from orbit" yet still didn't quite contain the problem. This movie was a "woman at war with war and corporations and all that bad stuff" type movie (like "The Terminator"/Sarah Connor).
The third movie was where Ellen Ripley casts herself into metaphorical "hell" (a lead works refiner) in the hopes that her sacrifice will stop the madness. She must've been inspired to do this by her memories of innocent Newt/Rebecca, or maybe some of the faith of the converted convicts who ran the lead works rubbed off on her, or maybe she's the heroin of the story and felt compelled to do this (or maybe she was competing with the Arnold, who ended one of his Terminator movies by having himself dipped in molten steel). In any case, the synthetic tries to convince her not to do this, and what Ripley doesn't count on is that "the corporation" has better genetics technology than that guy who used mosquito food and frog DNA to create a dinosaur theme park.
By the last non-prequel movie, Resurrection, there is no Ripley, only a somewhat humane half human creature that looks and acts like Ripley, who befriends a synthetic (and by this time, the people making the synthetics decided to go with the depressed, goth female prototype played by Winona Ryder). Hybrid Ripley and the Wednesday Syntho are on board a ship of mercs/space pirates, who are allowed (I forget why) to dock at a highly sensitive military installation that should've been much more secure (but what difference, at this point, does it make?)
Anyway, the prequels take a darker tone, much darker, bleaker, more Lovecraftian in terms of their outlook for humanity. Whereas synthos in previous Alien movies were virus-infected loose cannons, or corporate goons, or even just average Joe's helping to move the plot along, these prequel movies posit the syntho David as the surrogate of human destruction, the ISIS of the android world, seeking to declare a Caliphate of chaos. What can you say about this guy/thing? He prefers Wagner over Bach (obviously the first flaw in his programming). He reluctantly helps a Joan of Arc type character (Shaw) escape the a planet from which (we are lead to presume) distant relatives of human earthlings (who seem to have sort of a corrupt, ancient Roman feel to them) have created the perfect bio-weapon. This entire planet seems to have been a kind of "Area 51" for these mysterious ancestors, but of course, everything went wrong, and I suspect they overprinted their money too, and at any rate, they left this abandoned time bomb for us to find.
By some great miracle of determination and faith, Shaw and David make it to the planet. Shaw painstakingly repaired David. He did everything she wanted, but then he, well, he didn't exactly pay it forward when it came to how he treated her. All her kindness to him did nothing to repair his contempt of humanity. Years later, enter the Colony ship, Covenant, whose misfortunes and technical difficulties draw them towards the very planet David had ravaged with aliens, and claimed to be god over (while quoting Byron I think).
Covenant introduces two key characters, a woman who seems to remind David of Rapace's Shaw character, and Walther, a much saner/tamer iteration of David's prototype. There was a certain scene where Ridley was shamelessly pitching Blade Runner 2049. In it, David is attacking the woman I just mentioned. She stabs him with a rusty nail, and he retorts "That's the spirit" a la Roy Batty. Hey, you got to give it to Ridley Scott--poetic, crazy androids seem to be a thing with him. There are some great one liners between Walther and David ("One off note destroys a symphony", for example).
You're not supposed to walk away from a Greek tragedy with warm fuzzy feelings inside. Ditto with Prometheus and Covenant. Are they good movies? I appreciate Ridley's attempt at tragedy. I think they were okay, thoughtful movies. I thought the special effects/visuals were great. The fact that these colonists, especially the leader, a guy who should've seen the writing on the wall as far as David is concerned, made the plot a little tougher to swallow at some points. And I guess at heart I always like movies to end with at least some "seed of hope". It's what I loved about Star Wars--but Aliens is definately NOT Star Wars. I wrestled in my mind for a seed of hope in Covenant. The way David treated Shaw made it hard to see any seed of hope, in spite of the fact that many of the colonists, and the woman mentioned survived to the end of the movie. But yeah, I might watch it again
I hate to say it but I think these new alien movies (prometheus/covenant) are far more meaningful than the action packed extravaganza of Aliens and the depression of Alien 3 - Scott seems to have a plan - my guess is that David, aside from being the ultimate creator of the Xenomorph, will ultimately control the evil Wayland-Yutani corporation - and that this storyline will confront the questions it's posed. - I also think the Engineers might have created humanity as part of their war (they were manufacturing those weapons for a reason, right?) to be hosts for their bio-weapons.....
He does seem to be leaning towards dark tragedy & intrigue. I think your guess could be as good a trajectory as any, but in Prometheus one of the scientists confirms that genetically "they are us" which if that's true it would be pretty horrible to create children of your own flesh & blood just to use them as weapon delivery systems.