Polybius 1981 Hat

Polybius was allegedly a mysterious arcade game that had a very limited release by way of a couple of backwater arcades in a suburb of Portland. The history of the game is cloudy as there were all kinds of strange stories about how kids who played it got amnesia afterward, couldn't remember their name or where they lived, etc. Despite quite a bit of interest in Polybius and several FOIA requests, no concrete evidence of this game or the alleged CIA program behind it has ever been proven to actually exist, leaving Polybius as a mysterious arcade game with a distinctly unique urban legend status. The title screen attributed a company by the name of Sinneslöschen as the developer, not-quite-idiomatic German for "sense delete."