Sheep is a combination strategy and puzzle game, featuring light elements of war or battle simulations, built around a wacky story in which space-faring alien explorers from millennia ago devolve into domesticated sheep on Earth. Now their ancestors are trying to round them up by secretly enlisting the aid of two humans (Bo Peep and Adam Half Pint) and two animals (a sheepdog and a pet) through subliminal mind control.

Players take the role of the Earthly "herders" to lead the flocks through six worlds with multiple levels, eventually reaching special rendezvous point where they'll be loaded onto UFOs for the trip back to their home world of Ovis Aries. No direct control is exerted on the sheep so players must manipulate objects and obstacles, as well as rely on the strengths of each herder, to accomplish the tasks. Levels have time limits and a minimum number of sheep to be saved from each flock.