The White Laboratory is a sandbox style physics-based tower defense and RTS game in which you modularly build and command robotic structures. Use them to defend against or conquer other disobedient mechanical blocks on a facility floating in the atmosphere of a remote gas planet.
Too short with no multiplayer or modding support to add anything to it, not worth the money even if on sale. (either a multiplayer versus or just ANY steam workshop support would REALLY add a LOT to the game)