Xenonauts

Xenonauts is a strategy game in which you control a multi-national military organisation defending a Cold War-era Earth from alien invasion, using small squads of persistent soldiers to eliminate the extraterrestrials and recover their technology in turn-based ground combat. A detailed strategic layer allows you to co-ordinate the defence of the planet, using your interceptors to shoot down UFOs and researching captured artefacts to learn about your foes and unlock new combat