I'm just a little ways into it, but I don't like how situationally unaware the AI is in the game. They don't try to flank, call for backup, or anything that most common FPS do in today's games. You can get the drop on almost anyone and if his comrade is standing with his back turned you can get away with (murda!) literally.
Yeah, that's nice, and would show the Alien to be a badass, IF the guy he was killing wasn't begging and moaning, and the alien wasn't snarling every 1.2 milliseconds.
In the mulitplay, rail/scope sights would've been nice, and I'm not to fond of the grappling/block mechanic.
I prefer Rebellions original take on the Alien/Pred. If one of the other species got near you as a human you were dead. If a human caught an Alien or a pred out in the open, they were dead.
Realism over gameplay mechanics? Yeah. For me at least. I can't get over how stupid it feels for a 6' marine to be bitchslapping 8' tall badasses that physically manhandle humans in the film.