Arma 3 's upcoming Zeus mode gifts one or more players god-like real-time control of multiplayer scenarios. From several miles above ground you can set objectives, place vehicles and plant enemy troops as your friends march through your deathtrap. You can even call down thunderstorms - hence the Zeus title - trigger ambient war noises, initiate grand musical cues and create battles between the AI to create the powerful sense that your players are part of a wider battle. Essentially you're the hardcore military sim equivalent of that guy from the Truman Show who lives in the Moon.
Get a sense of the power and user-friendliness of the Zeus interface in this lengthy Bohemia Interactive livestream, in which the developers drop interesting tidbits. There can be multiple 'Zeus' players, for example, and Zeus mode will work with mods if you set up a modded scenario beforehand. An exciting new idea for a shooter mode, and free for owners of Arma 3 once it's out of beta. Very nice.