This game is a good addition to the Aliens franchise. It is an isometric real-time squad shooter with all of the classic Colonial Marine squad types: Sergeant, Gunner (smart gun), Medic, Techie, and Recon. A lot of emphasis is placed on stealth to avoid attracting unwanted attention, but it is implemented only partially okay; there aren't nearly enough spots where your squad can hide, despite lots of the surroundings being suited to do so which makes stealth unnecessarily difficult as your squad is exposed a lot of the time.
You've got some interesting placeables that you can set up. The classic one being the sentry guns. The sound they make when they fire is true to the movies. The downside with these is that they are unacceptably weak. I'd expect it to easily mow through aliens or [spoiler]cultists/Weyland-Yutani special forces[/spoiler] but they only do a trickle of damage over time. Same with the APC's squad support weapons; a vehicle weapon should make short work of any enemy. The sentry guns are handy though to guard chokepoints or alien spawns (represented by the red triangles on the map). Placing motion trackers around the map keeps track of moving baddies and you can use them as a one-time distraction to aliens to draw them into ambushes. Another disadvantage about the sentry guns is that they break whenever you use an elevator and takes wrenches to repair, which is annoying if you've already positioned them in strategic spots and have to backtrack to repair them.
One downside with the stealth system is that if any alien spots you (even the little facehuggers) it triggers a rather long hunted phase, which progresses the difficulty from easy to maximum aggression if you get spotted too much. It isn't really lore-accurate for a facehugger to spot you across the room when it's in its egg. A well-timed and aimed grenade from the grenade launcher can prevent getting spotted by aliens or facehuggers. In later levels this became difficult to avoid since there are so many alien spawn points on the map, and stealth becomes nigh-impossible when it gets to hard or maximum. You can always leave the map and re-enter it with a different squad of marines since they get exhausted which will reset it to easy, but this has its own challenges as [spoiler]the bombardment phase constantly ticks down the more days you proceed[/spoiler].
You can upgrade your marines and equipment which is handy, but if you're trying to level them all equally to level 10, you might not be able to do so in a single campaign. New Game+ is available though once you complete all of the missions which carries over their progress; as I'm writing this review at 31 hours I finished the main campaign.
The story is alright, about as engaging as Aliens Fireteam Elite but not quite as good as Aliens Isolation. The atmosphere and graphics are true to the retro sci-fi of the original movies (not the modern version like in Alien Covenant or Alien Prometheus). The bad guys are not very complicated, being [spoiler]motivated by money of course in exploiting the aliens, like in basically all of the Alien movies, or are crazy religious cultists[/spoiler]. There's also a questionable design choice in the last mission: [spoiler]you guide 3 characters from the story but your entire squad from the previous mission which were standing next to them didn't join them in the elevator. There were some pretty tough sequences since you're underpowered with those 3 instead of including your now-upgraded squads[/spoiler].
Still, even with a few flaws, it is a very enjoyable game if you like real-time tactics gameplay which isn't very common these days, and it scratches the Aliens itch.
