Warframe is an online free-to-play cooperative third-person shooter video game developed by Digital Extremes. Players control members of the Tenno: a race of ancient warriors who have awoken from centuries of cryosleep to find themselves at war with the Grineer- a race of militarized human clones. To fight back the Tenno use advanced exo-armor with unique abilities—the eponymous Warframes. Available missions are scattered across the planets of the solar system. Players can also access missions set in a pocket dimension known as void through the use of keys.