Well i completed it last night, playing as a Alien is just cool, but playing as a Predator is one of the best parts of the game, a predator game could really stand on its own two feet in my opinion, i really enjoyed that part.
It was a bit shorter then i thought at first, and you do go over the same areas but from the 3 different perspectives, and there are about 8 different large levels, the graphics of the Alien and Predator are fantastic, the audio of the game is also brilliant, i played the game on medium and it was quite tough, I'm not even going to attempt it on hard and forget nightmare.
As for the game after finishing it i would give it a 7/10, it could have been longer and had some more levels, but being a Aliens/ Predator fan i did enjoy it from beginning to end.
Pros.
Its AVP.
Great fun crawling about the walls as a Aliens or jumping down and taking people as trophies as a Pred.
Kill moves are right out of the movies
Audio is fantastic.
Cons.
Too short.
You go over the same levels from three different perspectives.
Too short.
Difficulty levels seem a bit high even on medium
Torch on the marine is useless and will for than once get you killed.
7/10