i seem to be the minority here...
i'm going to try and bring up every good and every bad thing about this game. i've never seen a game get so ram-sacked without it really deserving it. yes i did buy this but that honestly is not going to factor into this. i will not be biased. i like aliens and i like predators. i'm not a hardcore fan and the 2 don't always go good together, (the movies sucked balls, well at least the first one did) but they're cool. ok.
Graphics- this is one of the better looking games that i've seen this year. i'd rather look at this than Bioshock 2, without a doubt. there is a bit of a generic-ness to the menus, but everything has a nice blur to it and is pretty detailed.
Gameplay- jumping from tree branch to tree branch as an alien or predator is tons of fun and works just fine. it's fun starting out at one end of the map- while a dude is shooting at you, but then somehow ending up behind him without him even knowing what happened- then biting his head off. the only negatives i can think of - no aiming down the sights and no crouching. the melee aspect is fine. i don't always go for the prompted "block and combo", but when i do it usually works. i just like bashing them in the head and then pumping a full clip into them. heh heh.
CONTROLS- this is what i've seen the most complaints for. all i can say is there is a learning curve. you can do a lot of cool things in this game and pulling those cool things off is not a problem once you learn the, for the lack of a less serious word, "science" of every mechanic. i could see how you would think this game blows if you just played it for 5 minutes, but just give it time.
matchmaking- it does take a while to find a game. i recommend playing friendly games until they come up with a fix for the matchmaking, assuming they will. in friendly games you don't go back to the main menu when you finish a match so you can just play game after game. or you can just browse for a game yourself.
multiplayer- aside from the matchmaking, the multiplayer is really awesome. a lot of the modes seemed to be borrowed from halo. "predator hunt" is a lot like "juggernaut". it's where there's a predator and a bunch of marines and who ever kills the predator gets to be the predator. another halo-esc mode is "infestation", much like the halo mode "infection" you try and kill the aliens before you become an alien. those 2 modes are kind of similar but they're both fun. there's other call of duty like modes such as "domination". sneaking up behind people and executing them is a lot more fun when it's a real person on the other end.
campaign- a bit of a cheap/cheesy horror movie/game vibe to it. but there's some good "first person experiences" if you know what i mean by that- i.e being dragged down the hall by an alien, then capping him in the ass. i've completed a good chunk of the marine and predator campaign and haven't yet touched the aliens but i've had some good- creepy fun with it and can definitely say its not the worst i've seen. almost forgot, the checkpoints are few and far between and that can get pretty annoying.
enemy AI- i have to point the AI out. especially in the aliens, the way they scurry about seems very life-like and is creepy as hell. you never know where they're gonna pop out.
that's all that's ringing a bell for now. if anything, ripping peoples spines out is awesome.