Xenonauts

Xenonauts is a strategy game in which you'll control a multinational military organization that defends Earth from an alien invasion in the Cold War era. You'll use small squads of persevering soldiers to eliminate the aliens and recover their technology in turn-based ground battles. A detailed strategic level lets you coordinate the planet's defense by shooting down UFOs with your interceptors and examining captured artifacts to learn more about your enemies and unlock new combat equipment for your missions.