There's something conceptually terrific about the three-way dance that is Aliens vs. Predator, but Rebellion's rework of the formula--which has been around for well over 15 years now--flubs the execution in a lot of different ways. The franchise's class-based take on multiplayer combat still elicits a few thrilling moments, but the three single-player campaigns aren't any fun at all.
Aliens vs. Predator is all about the differences between the three playable factions. The Marines carry weapons, like the iconic Aliens pulse rifle and even more iconic Aliens motion detector, which blips out frequently enough to let you know that something's moving out there, but not often enough to serve as a direct map to your enemies. The aliens are a purely melee class that can crawl on walls, see well in the dark, and detect silhouettes of enemies through solid surfaces. Predators can cloak themselves, get two vision modes to help them see the other races, and are largely a melee class as well. But they can collect and use specific Predator weapons as they hunt. These weapons end up being especially devastating, but they're kept in check by low fire-rates and a finite amount of energy for your beam weapons.
So with two classes relying heavily on strikes, that melee combat needs to be pretty good for the game to work. But it doesn't fit with the action especially well, and the end result is a rock-paper-scissors-like system of strikes, blocking, and counters that feels out-of-place in the game's fiction and also isn't much fun to perform. The aliens end up feeling especially weak. These things are bred to rip out the throats of the opposition and claw them apart in the process. Standing still, holding down the block controls and waiting for your enemy to strike so you can counter just feels silly. These mechanics do, however, make AVP feel very different than your average first-person shooter, which is a nice reprieve from the standard rifle/shotgun/sniper/rockets gameplay that you've come to expect from the typical sci-fi first-person shooter. The game offers a variety of different multiplayer modes, too, but on the 360 version, it was often hard to find players. You may have to wait around for five or 10 minutes before collecting enough players to get a game started.
Of course, that doesn't forgive the game's single-player portion, which drags you through the same dull events from three different perspectives. At best, the instruction you get on the use of your class's tools makes it a passable tutorial for the multiplayer. At its worst, though, AVP contains multiple scripting bugs where things that were supposed to happen simply didn't, forcing me to restart at the most recent checkpoint and hope that the game would carry forward. Also, the AI can't pilot an alien very well at all, like it can't deal with the concept of running up walls. If there's a pillar between you and an alien, it'll run up the side of it and start twitching and spinning around. It gets its bearings after a few seconds, but it looks pretty terrible. It'll take around six or seven hours to work through all three campaigns on the default difficulty setting, but they're not really worth seeing through to their conclusions.
That's really the largest problem with Aliens vs. Predator. There's no one solid aspect of it to make up for the other, busted-up parts. You're left with the impression that the single-player was an afterthought and that multiplayer was the focus. But even the multiplayer is saddled with enough flaws to make this game missable.