Aside from its storied history, Aliens vs. Predator's main appeal is its three disparate campaigns, in which you respectively take control of a marine, an alien, and a predator. Each campaign has its strengths and starts well enough. The first two levels of the marine story, which plays as a fairly typical first-person shooter, are dark and creepy, making good use of atmospheric lighting to enhance the tension. Your first encounter with a creepy-crawly xenomorph is properly nerve-racking and will have you searching about in the dark, using your handy motion tracker to try to figure out exactly where it is (while trying to bear with the tracker's incessant beeping). Playing as the alien, your escape from the confines of a laboratory features some good old-fashioned bloody head-chomping, and there is some short-lived fun in crawling all over the walls and ceilings. And the predator offers his own delights. It can be fun to leap from surface to surface while you gaze down at hapless marines as they stroll underneath and you prepare for a gloriously disgusting kill.
But in each campaign, the thrill wears off quickly when you discover that Aliens vs. Predator botches a lot of the basics, and what seems thrilling at first becomes downright tedious as you struggle with poorly designed levels and gawky gameplay. For example, the dark thrills of the first marine levels give way to tedium once you leave the dark behind and enter jungles and temples, which are far less interesting and make shooting the grotesque xenomorphs no different from shooting up raptors in Turok--except that the levels are much more confined and straightforward. Eventually, you'll learn that the same trick in combat dispatches aliens almost every time: block their attack, smash them with a melee attack, and shoot them when they're down. This doesn't work when there are a lot of them, but it gets the job done more often than not. That doesn't mean the marine campaign is a cakewalk; some levels feature annoying choke points or give you too little room to maneuver, which makes certain sections feel more cheap than challenging.
The alien campaign is interesting at first, thanks to a number of cool abilities that are initially fun but ultimately can't compensate for some major mechanical malfunctions. For instance, it seems fun at first to crawl around on walls and ceilings, until the awkward controls suck all the pleasure out of it. You are supposed to hold the right trigger to scamper onto a wall, but in actuality, there's no consistency to wall- and ceiling-climbing. You'll crawl onto some walls and outcroppings willy-nilly whether or not it's what you intended to do. You'll try to activate one of the game's super-picky button prompts and jump onto a wall instead, or wrestle with the controls and camera trying to do something as simple as slither into a vent. You'll eventually learn to wield some control over the alien's fickle movement, but even then, moving around isn't all that enjoyable. You never feel in control of an actual creature; instead, it's as if you are floating just above the ground.
Sadly, the troublesome movement gets in the way of your sneaky attacks. It can be mild fun to get in position above an unsuspecting marine and pounce, but the unwieldy movement and haphazard level design make it much more enjoyable just to stay on the ground. For example, you might try to pounce from a wall onto a passing victim, only for a beam to get in the way and cause you to drop right in front of your enemy without doing a bit of damage. Yet as clunky as it gets, you'll have fun when everything comes together in just the right way. Playing as the alien is all about hit-and-run tactics, speeding close to your prey or ambushing him, and either taking him out with a swipe of your powerful tail or speeding away if the action heats up. Executing a well-planned attack can be fulfilling, though the game doesn't create many such moments, leaving you to make them of your own accord.
