OK I just tried it out for a bit. Something about the visuals feels sort of dated, and the map design does as well (for the 1 map available). My biggest gripe thus far is that the marine fucking sucks. The pulse rifle does shit for damage and you lose all visibility to it's muzzle flash, and the shotgun isn't much better in the damage deparement. I shot an alien in relatively close range 4 times, then he 2 shot me with a melee. I found that the best way to deal with an alien (unless you can catch him by surprise with nowhere to run) is to melee him when he gets close, which knocks him down and gives you a second to throw more bullets at him. Maybe I should be blocking? That seems really stupid, but maybe that would help. As a marine, marines are the easiest kills (whoever sees the other first wins, unless one has a shotgun, then he wins). I think melee is just really strong in the game, and marine is the most range-based race.
Are the alien or predator fun? I have no idea. The game seems to only allow for 3 of each race. So the instant the lobby forms, everyone jumps into the alien and predator slots, and if you're too slow you're stuck as a marine. Since the matches the game sets up for you are 8 players, that means 2 people are stuck as marines wether they like it or not. PC and console demos both use matchmaking, and after a 10 minutes game, it dumps you back to the matchmaking screen instead of letting you play another round.
The game is something I definitely want, if just for the single player. But just from the visuals and map design, I'm questioning if it would be worth playing to anyone who's not into Aliens or Predator. I may cancel my preorder and get it when it drops in price a bit. I wish I had a single player demo to mess with.
EDIT: I managed to get an alien slot, and it's way, way more fun. It's also a LOT easier to actually kill people. You have a really slow and strong attack, and a faster light attack. The strong attack 1 shots marines. There's a context sensitive grab thing, but by the time you get that close to someone, they're aware of you and it's a bitch to pull off. I also miss the leap attack from AvP2. You have a "focus" key that when held and targetting a player allowed me to jump at them, but I don't think it did any damage.
I think the visuals aren't really that bad, but it feels sort of like they made the game on an old and dated engine. There's blurry textures, and the environments seem pretty simplistic. I think these, plus the sounds (especially footsteps) really remind me of
Alien Resurrection for PSX. No it doesn't look like a PSOne game, but it reminds me of that in style, which oddly makes me want AvP more. It also makes me wish I had a PS2 to play AR again.