I copy and pasted something from the wiki about it: The urban legend says that in 1981, when new arcade games were uncommon, an unheard-of new arcade game appeared in several suburbs of Portland, Oregon. The game was popular to the point of addiction,[1] with lines forming around the machines and often resulting in fights over who would play next. The machines were visited by men in black, who collected unknown data from the machines,[1] allegedly testing responses to the game's psychoactive effects. Players supposedly suffered from a series of unpleasant side effects, including seizures, amnesia, insomnia, night terrors, and hallucinations.[2] Approximately one month after its supposed release in 1981, Polybius is said to have disappeared without a trace.[3]