Polybius is an arcade game that rose from obscurity in 1981. The game was said to have included effects that induced psychological effects in the people who played it. Players described symptoms including amnesia, night terrors and the tendency to loose all desire to play video games. Then, only a month or so after its appearance, it vanished just as suspiciously as it arrived. Though there is no evidence of it ever existing (other than the image above of course), hundreds, to thousands of gamers have come forward saying they played the game.