It's the year 2140, earth is almost completely destroyed after numerous wars and environmental catastrophes, and the people primarily live underground. The two enemy parties are the United Civilized States and the Eurasian Dynasty. In this RTS game, both are trying to conquer as much land as possible.
Earth 2140's game concepts overlap with those of the Command & Conquer lineage - mine resources, build units, and send them into battle with an enemy which must be tracked down. The two sides have different units, with the UCS advantaged by its Mercs and robotic infantry. There are cinematic cutscenes for each mission