Mario Demo (lost Virtual Boy tech demo; 1994)
At Shoshinkai 1994, Nintendo demonstrated their upcoming video game console, the Virtual Boy. To demonstrate its stereoscopic 3D effects, they made a brief demo featuring their most recognized character, Mario. A rendered image of Mario appeared under the Virtual Boy logo, and then the logo flew towards the viewer letter by letter.
It is unknown if this demo was on a cartridge or programmed into the prototype console. Regardless, the demo has not resurfaced.