Killswitch is a game(survival horror) that was supposedly created by Soviet gaming company Karvina Corporation in 1989. Not many copies of the game were made, it was popular with soviet kids, but rare.
The objective of the game was to navigate these haunted coal mines and fight creatures and ghosts. You could play with either a girl or an ivisible demon. It was hard playing as the invisible demon since you could not see the character so most people chose to play as the girl. Unfortunately, No one ever completed the game with the demon, because upon beating the game all trace of it would be erased from your hard drive.
Yamamoto Ryuichi bought an unopened copy of this game on ebay for $733,000 so he could upload his playthrough to youtube. He only uploaded one video and that was of him staring at the computer screen and crying.