Polybius

In 1981 a mysterious arcade game appeared in the suburbs of Portland, Oregon. Its name: Polybius. Rumor has it that this shooter was a good time, albeit with some pretty gnarly side effects, namely nausea, nightmares, seizures and suicide attempts. Despite this, crowds lined up around the block to play it. These gamers were said to have been monitored by mysterious men in black who came to gather data from the machine and its players. Then, suddenly, not long after it appeared, the machine was gone. GamerPro says reports of the game's existence are "inconclusive."