Review
If there is one thing Alien Trilogy has in spades, it is atmosphere. For example, pretend you're walking through the dark corridors of the LV426 (the ship from Aliens) when all of a sudden your motion tracker begins to beep excitedly. The dot appears to be 10 feet in front of you and you can barely see a foot ahead. Your heart begins to race and your hands begin to sweat as you take a gulp in hesitation and step forward. With your finger on the trigger, the alien leaps at you. From the moment you sense its movement, you begin to blast into the darkness with only your gun to light up the hallway.
Moments like these are commonplace in Alien Trilogy. You will fear this game. Wanton blasting is futile because you must conserve all the ammunition possible--sometimes more is very hard to find. You will more than likely always be in desperate need of it and you'll have to go exploring for health and ammo packs. All the while, you have a main objective hanging over your head and a motion detector that won't stop beeping. Needless to say, this is a tense and thrilling adventure.
The level design (over 30 missions in all) and the detail within is truly staggering. Unlike a lot of first-person shooters, you never feel that you're running down the same corridor over and over again or doing the same thing repeatedly. Each location is well textured with plenty of darkness and lighting effects to go around. The enemies (face-huggers, aliens, and queens) are usually placed in such a way as to scare the living daylights out of you.
The most important factor of game play is the way a game controls. Alien Trilogy does not disappoint. Your control pad is completely configurable with everything you could want in the world of Aliens at your fingertips. These well-placed controls are very useful when trying to blast a whole nest or swarm of aliens. The frame rate is adequate and smooth throughout the entire game and allows you to maneuver around your foes comfortably.
In conclusion, if you are a big fan of the Alien films or of scary, first-person shooter games, you owe it to yourself to pick up Alien Trilogy. It is crammed with enough darkness, mood, atmosphere, and alien monsters to keep you on the edge of your seat throughout. Be warned that it is a pretty challenging game filled with long, complex levels, but people willing to overlook this will relish its world for weeks.
Graphics 
Though the sprite-based enemies detract a little from the believability, the atmosphere and mood is great. Everything has a dark and creepy theme that makes for a truly suspenseful journey.
Sound 
The sound track is both upbeat and stirring and the sound effects (aliens and weaponry) are dead-on perfect and horrifying.
Enjoyment
If you enjoy being scared out of your seat and walking through alien-infested corridors while trying to preserve ammunition and not get killed, Alien Trilogy is a very scary, enjoyable, and traumatic experience. It is not for the squeamish.
Replay Value
There are over 30 long missions that will keep even the most seasoned veteran busy for a long time. Each level is filled with secrets that give you minimal incentive to replay. A two-player option would have been nice, but the strong single player experience makes up for it.
Documentation 
The manual is standard and offers advice as to how to set up your controls and play the game effectively.
