Marines Campaign: It's reminiscent of almost every other dark grimy FPS of its era, at most it's just boring.

Xenomorph Campaign: Underwhelming Arkham stealth system mixed together with a character who moves too fast, and can climb on almost all surfaces, making it more of a challenge of not throwing up rather than a challenge on the game's part. It's the worst campaign of the 3.

Predator Campaign: The most fun I've had during the whole game. If they made the hand-to-hand combat better and the AI more responsive it would've been perfect.