X-COM: UFO Enemy Unknown

You are in control of XCom; an organization formed by the world's governments to fight the ever-increasing alien menace. Shooting down UFO's is just the beginning; you must then lead a squad of heavily-armed soldiers across different terrains as they investigate the UFO crash site. Tackle the aliens with automatic rifles, rocket launchers and even tanks in the struggle to retrieve useful technology, weapons or life forms.

Successful ground assault missions will allow XCom scientists to analyze alien items. Each new breakthrough brings you a little closer to understanding the technology and culture of the alien races. When you engineers have amassed sufficient research data on their superior weapons and craft, they'll be available for your troops to use.

You must make every crucial decision as you combat the powerful alien forces. But you'll also need to watch the world political situation; governments may be forced into secret pacts with the aliens and then begin to reduce XCom funding.