Released the same year as Killer Instinct and during the reign of the Mortal Kombat series, Primal Rage was part of an overall trend toward more sophisticated (and violent) graphics and gameplay in arcade fighting games. Following a cataclysm that regresses the world back to the Stone Age, seven godlike creatures emerge on this new Urth and fight over the fate of the planet, worshipped by the remaining humans. Primal Rage's key differentiator was its non-human characters, including dinosaurs and giant apes, brought to life using novel stop motion animation techniques. The game spawned not only a significant arcade following, but numerous console versions as well as a popular toy line and a sequel, Primal Rage II, that was never widely released but can now be played via emulation.