space-themed video game, Kerbal Space Program, rocket simulation, realistic physics, spacecraft construction, space exploration, green humanoid characters, Kerbals, sandbox mode, career mode, science mode, planet Kerbin, Mun landing, interplanetary travel, vehicle assembly building, launch pad, mission control, astronaut complex, research and development, modding community, Steam platform, educational gameplay, physics-based flight dynamics, orbital mechanics, procedural terrain, celestial bodies, atmospheric re-entry, heat shield, staging sequence, thrust-to-weight ratio, delta-v efficiency, aerodynamic design, space station construction, satellite deployment, exploration missions, Munar orbit, EVA activities, resource mining, cost management, budget constraints, science points, technology tree advancement, custom missions, player-created content, mod support, expansion packs, Making History, Breaking Ground, realistic lighting, detailed textures, 3D models.