It can be an online marine FPS and also still be a deep RPG-ish type game with deep story at the same time hopefully. There's so much potential with what can be done good here, its amazing. But hopefully they dont f**k it up. I'd love to travel between different colonies and meet new human characters(friend or foe), and maybe have squad mechanics, and tense moments low on ammo welding doors shut and setting up turrets while aliens come from everywhere. f**k ACM, imagine what it COULD have been, but done right, on steroids. Having moments without any weapons Alien Isolation-like, and having to creep around to regroup would be essential, too.
A good BLEND of Alien/Aliens is key here. They need to combine the horror of alien isolation with the 'action'/tension of Aliens. They should take the alien isolation AI, and pretty much apply it to multiple Aliens at once in gameplay(with additional improvements like wall-climbing, etc). Aliens should be to scale. Ammo should be effective, but scarce. Acid blood should hurt. A lot. (and possibly deform geometry). Animations for marines and especially the Aliens of course should be TOP NOTCH. Mechanics should be deep. Welding/cutting doors, arming/setting-up turrets(with limited ammo), barricading with objects around the room, setting up cameras etc.....it should be like the ultimate seige-game. Fuzzy monitors should be set up where you can see in-gameplay the aliens coming in real time.
And of course other character moments, drama, world building etc. It should be a long well-writen, believable, story.
I'd like W-Y and the movie's(Alien 1-3 only) plots to be relevant somehow, but not necessarily in the spotlight. This would all need to be great in execution of course. Anyway, this is just my dreams for a great alien(s) game, and although far-fetched, a new alien game announcement is always a time to appreciate and get a bit hyped for!