Xenonauts (STEAM KEY / REGION FREE)

Windows
OS: Windows 8 / 7 SP1 / Vista SP2
Processor: Intel 2 GHz
Memory: 1 GB RAM
Graphics: Integrated Graphics
Hard Disk Space: 3 GB available space
Additional: 1280x720 pixels minimum
Mac
OS: OSX 10.6 or better
Processor: Intel 2 GHz
Memory: 1 GB RAM
Graphics: Integrated Graphics
Hard Disk Space: 3 GB HD space
Additional: 1280x720 pixels minimum
Linux
OS: Any Linux distribution since 2010
Processor: Intel 2 Ghz
Memory: 1 GB RAM
Graphics: Integrated Graphics
Hard Disk Space: 3 GB HD space
Additional: 32bit libraries (may or may not be required depending on your system), 1280x720 pixels minimum
Languages: English

The game takes place in the alternate world of 1979, during the Cold War, when the USSR and the US join forces to combat the alien invasion. As in the original UFO Defense, the gameplay is divided into strategic and tactical parts.

- In the strategic part, the player creates and develops bases, recruits personnel for them, conducts research, equips soldiers, and wars against alien ships.
- Tactical part is a step-by-step ground battle. One of the most significant innovations compared to X-COM: UFO Defense - a tactical air battle between fighter-interceptor earthlings and "flying saucers."
In ground missions, alternative victory conditions are introduced, eliminating the need for the player to destroy all aliens on the map, as well as the player-friendly soldiers controlled by the computer. Game developers expressed their approach to tactical combat in the following way: "You have to lose units because of your mistakes, not because of bad luck, so a weapon like a blaster bomb, capable of destroying half of your unit, was removed and replaced with weapons that a skillful player can withstand"