Iron Sky: Invasion is an engaging space fighter simulator that blends classic dogfighting mechanics with strategy and RPG elements. Set in an alternate universe where players defend Earth from an invasion by Moon Nazis, the game allows players to pilot various spaceships equipped with an arsenal of weapons, including laser cannons, missiles, and drones. Players can freely explore space, engage in ship-to-ship combat, and take down massive enemy vessels like the Siegfried-Class Zeppelins while managing resources and tactical decisions.

The game features a tactical map that helps players identify enemy positions and ongoing battles, guiding their actions in real-time. Players can accept missions from different nations, leading to unique rewards and new ship unlocks. Docking at allied space stations enables players to recharge weapons, upgrade their ships, and switch between various available vessels, all while scavenging resources from defeated foes to enhance their combat capabilities.