The Colonial Marines play very much like humans in any other class-based shooter. You get a choice of weapon loadouts every time you spawn, with weapons like shotguns, pistols, and grenades. A key difference, though, is that you never really feel invincible. If a Xenomorph gets close to you, you will go down very fast. That's the power struggle between the two races: Humans want to use guns to keep the alien players far away from them. Xenomorph players want to get in close as quickly as possible because if they do, the human is as good as dead. We found the shotgun to be particularly useful at dispatching enemies, but using it risked allowing aliens to get dangerously close. Tapping the left bumper to bring up your motion scanner as a human can also be an important key to victory, but it comes at the cost of not having your weapon ready.
Staying with the other humans on your team is essential. In addition to being faster, more agile, and able to traverse the map in different ways (such as on ceilings and through vents), Xenomorphs can see through walls. A good team of them will spot a solitary human soldier and swarm him immediately. When that happens, the human doesn't stand a chance. At least one alien has the ability to latch onto an opponent and kill him in seconds. The player who is attacked has no way of defending himself when this happens -- his survival rests entirely in the hands of his allies, who have precious few moments to shoot the attacking enemy off before their friend dies.
We didn't get to see a lot in terms of extra abilities or special weapons, but we did see one power-up example from both sides. Near the center of the map we were playing sat a collectable item for both the humans and the aliens. For the aliens, the item allowed the player who picked it up to "evolve" into a much larger and more powerful beast, which was capable of plowing through humans and took a lot of firepower to take down. For the humans, the bonus item was the smart gun: a weapon that can lock onto targets in view and auto-aim at them in a mini-gun- like fashion, allowing its user to mow down enemies quickly. We were told that the functionality and/or availability of these power-ups may be different in the final game, but they should show up in some form.
As has come to be expected in competitive first-person shooters, performing actions (kills, assists, rescues, etc.) will earn you points that go toward unlocking new weapons and abilities. For example, after every match we played we earned enough points to unlock a flamethrower weapon. Unfortunately, stats were reset at the start of each game, so we never got the chance to see it in action.
One interesting feature, though not entirely unique, is that progression in multiplayer will affect progression in single-player and vice-versa. So you might unlock weapons in multiplayer that you can bring into the campaign, which could change that experience. "It's one of those things where, when you invest a lot into a game, you want to make sure your investment carries over, so we want to make sure you can replay the game a lot," Brian Burleson, Aliens: Colonial Marines
senior producer, told us. "We made it so if you buy a new attachment for your gun or new grenade or whatever the new elements are, you can use them in either single-player or multiplayer, and that changes the game."