Before Metal Gear Solid, Hideo Kojima was allowed to work on a variety of titles without risk of death threats and/or violent confrontations on the street (usually by people in cardboard boxes). One of the games that he worked on was a cyberpunk adventure called Snatcher, and Kojima wanted crazy things to be happening to the player even then.
"Back when I was making Snatcher, which is a PC game – at the time we used floppy disks," Kojima explained during an interview. "One thing that I wanted to do that I wasn't able to do was that I wanted to have a secret message on the disk — actually have something written or printed on the disk."
"So maybe when you put it in your disk drive and you're playing for about fifteen minutes, the heat from the disk drive interacts with that chemical and creates a certain smell. It smells like blood or something like that," he explained. "And when you pull it out you see like a dying message on the disk. That was actually an idea I had for the original Snatcher but unfortunately I got yelled at for it and they didn't let me do it."
Source: Joystiq
