Aliens: Colonial Marines is a squad-based first-person shooter in which the player controls four Colonial Marines, each with a different personality and primary weapon. Each player character can carry additional weapons including a flamethrower, pulse rifle, smartgun, pistol, RPG, and many types of grenades. The player controls one marine at a time, issues orders to the others using context-sensitive commands, and may switch between characters at any time.
A mod that changes the gravity in Colonial Marines to be lower (single player only). Check it out and let me know what you think in the comments!