The game’s challenge came not from puzzles or scripted events, but from the game’s accurate (if slightly simplified) application of orbital mechanics and Newtonian dynamics. The closest thing to a score counter was the altimeter that showed how far your craft was above the planet’s surface, and the only way to “win” was to put its little green occupant, the titular Kerbal, back on the ground in one piece.

There was no story to follow, or enemies to battle. The sandbox game allowed players to cobble together rockets from an inventory of modular components and attempt to put them into orbit around the planet Kerbin. Kerbal wasn’t even an official company initiative, it started as a side project by one of their employees, Felipe Falanghe. Until that point the company had only developed websites and multi-media installations. Just a few weeks before Atlantis embarked on the final flight of the Space Shuttle program in 2011, a small Mexican company by the name of Squad quietly released Kerbal Space Program (KSP) onto an unsuspecting world.

Joystick ksp mac