UFO: Alien Invasion v2.2 Free Full Game
 

Developers of the free game UFO: Alien Invasion have released a new version of this turn-based tactical combat strategy game inspired by the X-Com series and powered by a heavily modified version of the Quake 2 engine. UFO Alien Invasion offers tactical combat against hostile alien forces which are about to infiltrate earth at this very moment. You are in command of a small special unit which has been founded to face the alien strike force. To be successful on the long run, you will also have to have a research team study the aliens and their technologies in order to learn as much as possible about their technology, their goals and the aliens themselves. Visit the official website http://ufoai.net/ for more details.

UFO: Alien Invasion v2.2 Free Full Game for Windows (384.86MB)
http://www.gamershell.com/download_22791.shtml

UFO: Alien Invasion v2.2 Free Full Game for Linux (396.82MB)
http://www.gamershell.com/download_22792.shtml