Aliens Vs Predator has three campaign's; Aliens, Predator and Humans. The Alien campaign is mainly stealth and surprise attacks, the Predator campaign is mostly about brutal force and strength. The Human campaign you play a soldier who is caught between the other two characters, the Marine campaign is mostly a scary one.
Story -- 4.5/10
The story is very weak, it is completely stolen from the Alien Vs Predator movie. In which they find a big pyramid thing full of aliens in which the predators hunt them. It doesn't go into detail, or really mention whats going on. The main focus of the game seems to be the action; however the campaigns are very short. About 4/5 levels for all three character types.
Game Play -- 7/10
The game does however make a come back with its very unique game play. For the Marine character its basic first person shooter set-up. For Predator it's the same type but a very different feel, with the head's up display it almost feels as if you actual are a Predator. With the Alien it gets full marks however; it may not feel very "Alieny" but the great camera movement, fighting and the ability to climb on walls submerges you into the Alien instinct.
Online -- 5/10
The multiplayer is ok, ranging from classic Death Match to the ever so popular Survivor, it wont leave you wanting more. If that's a good thing, for pc user's you will be using Steam to play online which is one of the most popular online computer community's so there are plenty of people to play with.
Graphics -- 7.5/10
The graphics are very good, the weapons, environment, character's and lighting all seem very realistic. The environment, especially for the Marine campaign, is very clever; plants that look like Alien heads, vines that look like Alien tails, burst pipes that look like drooling Alien's and falling rocks that look as if an invisible Predator has landed near you. All this create a very uneasy mood.
There are a few extra's, in the Marine campaign you can find hidden dairy's that give you a deeper back story to some characters. Other than this practically nothing else.
Overall I would say it would have been much better with a longer campaign, you could complete the whole thing in a single day. The multiplayer is ok, but would only really appeal to hardcore fans of the Alien Vs Predator series. One thing that bugs me is that it force's you set up a Steam account which is ok, but if you bought this as a gift for some one sort of takes out the fun. Just thought I'd mention that. Overall I would say its a good fun game but I would buy it as cheap as you can find it and the "Limited Editions" and/or others aren't worth it.
Oh and if you are buying this and you don't have the Internet don't buy it on PC, you need an Internet connection to verify the serial number for the game.
Hope this was helpful =)