Not as bad as some make it out to be.(Possible spoilers)
Story: Now, this was supposed to be a true sequel to 'Aliens' and well... it is not. The story itself has it's moments, but never really captures that feeling of the films and at times tries too hard to do so. While there are some references to characters from the movie( such as some of their weapons and characters within the game mentioning their names) it never manages to capture the magic of the films.
Graphics: Yes, one of the major complains of this is the visuals. All I have to say is that if you have played Duke Nukem Forever, then that is what you are getting in the visual department.
Sound: Now the sounds of the game is one of the biggest strengths. The guns themselves sound and feel right when shot and the Xenomorphs screams sound decent. The voice acting in my opinion is outstanding with some very amusing lines from some of the cast of the films lending their talents to the game.
Gameplay: The gameplay itself is very enjoyable, especially the multiplayer section. The campaign itself is not the best, but still pretty fun. Some of my biggest gripes is of course the A.I. particularly from your friendlies; they are about as useful as cutboard cutouts and sometimes just get in the way. You can play the game with a buddy for some splitscreen action, which only makes the campaign a little more enjoyable.
The multiplayer is where the game makes up for some of the campaigns shortcomings. With modes such as Team deathmatch, extermination, survival, and escape(one of my favorites). The ability to customize your marines or even your Xenos' is very enjoyable and if you're playing escape, it can get very hectic and very fun.
Overall: While it may not be the "true sequel" to a beloved franchise; the game is still rather enjoyable. But with those that are concerned with the length of the game( it's only about 3-5 hours give or take) or are single player gamers, then this is might be worth a rent or wait for a major price drop.
Note: This is my opinion of the game and I apologize for any grammatical or spelling errors I no doubt made.