Aliens was an iconic movie that remains an industry classic, and Aliens Colonial Marines was designed and intended as a direct sequel to the film. For how long the game was in development, fans expected a pretty good game to come from the classic James Cameron film. In retrospect, maybe they should have worked on it a bit longer. Instead of giving a feeling of terror, of being hunted, the game feels like every other shooter you've ever played, except that you're way overpowered, turning combat into a shooting gallery. The only possible saving grace are the multiplayer modes; unfortunately, these won't be fleshed out until a DLC package is released with more maps. The graphics are pretty bad as well, and the game is marred by a number of technical issues.
The story mode in a game that is supposed to come as a sequel to the horror/action film Aliens should impart some kind of sense of fear or anxiety while playing. At the very least, you should feel rushed and harried. Aliens Colonial Marines completely fails on this point. Instead, you get a game that simply feels like most other shooters, with some notable, and negative, exceptions to the rule. First of all, the AI is absolutely terrible. Both your teammates and the enemies are unintelligent and predictable. Also, you can carry as many guns as you want, and the weapons you have are overpowered, making the game feel much too easy. The campaign playthrough lasts around six hours, and you probably won't ever play it again. You'll feel a sense of elation and nostalgia at first (if you're a fan of the movies), but that's about it, and that feeling quickly wears off when faced with the frustrating gameplay.
Multiplayer isn't so bad. The best mode that the game has is called escape, which is eerily reminiscent of a Left 4 Dead mission. You run along with a team of marines, rushing to weld doors shut behind you as you fight off Aliens and try to escape. If that's all the game has to offer, you're better off spending your money elsewhere.
Some of the biggest complaints about the game come from its graphical quality. Problems run rampant, with everything from aliasing and low resolution to world objects (like your gun) simply disappearing from view for a while. Critical reviews of the game were mostly negative. IGN rated the game a rarely-seen 4.5/10, and aggregate scorer Metacritic scored it at 49/100. User reviews on Metacritic rated it even lower, with an average score of 4/10. Players mostly complain about the poor graphical quality and stunningly horrid AI, with hordes of Aliens simply charging you from the front with no intelligence whatsoever.
It's very difficult to put a positive spin on this game at all. If you're a diehard fan and want the game for that reason, wait a month and get it on sale. Until then, don't waste your money.