X-COM: UFO Defense is an extremely realistic strategy game featuring a unique blend of resource management and turn-based tactical combat. <br><br> X-COM is a covert organization funded by the world's governments. As the commander of X-COM, you have to investigate, and possibly defeat the alien invasion. <br><br> Your scientists research new technologies, weapons, and aliens while your engineers built your weapons, and other stuff. In the turn-based isometric tactical combat, you position your soldiers, and attack them to various targets from turn to turn. The same is true for the aliens too.