Gamers control four giants who create geographic features, plants, and animals and then watch humanity react in Reus. Players can use the Ocean Giant to create oceans and domestic animals; make forests and fruiting plants with the Forest Giant; control mountains, deserts, and minerals with the Rock Giant; and create swamps, exotic animals, and herbs with the Swamp Giant. Balanced production from the giants provides Food, Wealth, Technology, and Prosperity, but an explosion in resources creates Greed, which can trigger humans to attack one another, or fight the giants.