I've done up a super-basic but usable bit of info for the OP if you wanna use it. Most of it is from Wiki but at least will explain some aspects of the game for those that aren't aware of it!
Release Date : 12th February 2013
(Xbox 360, PC, PlayStation 3). Wii U TBC
Aliens: Colonial Marines is an upcoming video game in development by Gearbox Software and is to be published by Sega for
Microsoft Windows, PlayStation 3, Wii U and Xbox 360. The game is a first-person shooter based on the characters and creatures of the Alien franchise, particularly the film
Aliens.
Aliens: Colonial Marines is a first-person shooter which puts the player in the role of a United States Colonial Marine named Cpl. Christopher Winter. The player will have access to iconic weapons from the movie such as the
flamethrower, pulse rifle, smartgun, shotgun, pistol, RPGs, and robotic sentry turrets. Players will also be able to use welding torches to seal doors and motion trackers to detect unseen enemies.
Described as a true sequel to James Cameron's film, the story of Aliens: Colonial Marines takes place after the events of the second film, Aliens. At PAX East 2012, Gearbox Software's Community Manager confirmed that the game is considered an official part of the Alien franchise's canon by 20th Century Fox. Much of the main plot was written by Battlestar Galactica writers Bradley Thompson and David Weddle.
The story is told through the eyes of Corporal Christopher Winter, a Colonial Marine who is part of a search and rescue team sent to investigate the U.S.S. Sulaco in search of Ellen Ripley, Corporal Dwayne Hicks, and the rest of the missing marines who were dispatched to LV-426. The Sulaco, and the derelict alien spacecraft from Alien as well as LV-426 itself will all serve as environments in the game, as well as other locations yet to be detailed.
Single Player Campaign
The game includes a story-driven single player campaign mode, where players will earn experience points when killing enemies and completing certain objectives. These experience points will allow players to customize the appearance of their character, purchase upgrades for weapons, and unlock other skill sets, all of which carry over to other gameplay modes.
Multiplayer Modes
Aliens: Colonial Marines features a campaign with dynamic drop-in/drop-out cooperative multiplayer for up to 4 players online or 2 players locally via split screen. Competitive multiplayer has been confirmed, and Gearbox has shown Aliens vs Marines team deathmatch 6 v 6 gameplay, as well as a 4 v 4 objective mode called Escape, where the marines team must reach an evac point while the alien team must hunt and stop them. Other modes include Survival, which pits four marines against hordes of Aliens in a confined map.