UFO:Alien Invasion is a great looking turn based strategy game inspired by the X-Com games of old.

However UFO:AI has been given some great treatment such as utilising the Quake 2 engine for the updated 3D graphics.

There are two game modes in UFO:AI; Geoscape Mode and Tactical Mode.

The Geoscape Mode puts you in control of the details of running a mission from strategy to managing finances, bases, aircrafts and squads. In Geoscape Mode you wil also be responsible for research, buying and producing as much as your budget allows.

The Tactical Mode is a turn based game which puts you in control of the actual squads where you issue orders to squad members. This is effectively controlling a mission at the ground level which is set in the Geoscape mode. Each of your squad members has a certain amount of moves, or Time Units (TU's) in which they can move or fire weapons. When those turns are used up then the aliens take their turn.

As well as these game modes UFO:AI also has some great multi player features which allow you to play over a LAN or the Internet. In co-operative you can have up to 3 teams of 6 players. Or play head-to-head with Humans Vs Aliens.

UFO:Alien Invasion has got to be one of the finest examples of free software available.