In an interview with Metro, Jeremy 'Jez' San of Argonaut Software fame revealed he helped design a virtual reality gaming system named the "Super Visor" for Nintendo, but the system was ultimately cancelled in favour of the Virtual Boy.
Early iterations of the Virtual Boy also included a gun that could be set on a flat surface, which would project a 3D hologram-like image into the air.
The original prototype for the Virtual Boy was blue and was actually supposed to be worn on the player's head like goggles. It had a screen/pad on the controller, the purpose of which is unknown.
Even though there was an expansion port for two-player modes, the cable that made this possible was never released due to the fact that the system was discontinued so quickly.
A Full color Virtual Boy was impossible to release in 1995 due to the fact that high-efficiency blue and green LEDs only became available in 1996. The Virtual boy, which uses an oscillating mirror to transform a 1-D line of dots to a 2-D field of dots, requires high-performance LEDs in order to function correctly. Without the high-efficiency blue and green LEDs, the virtual boy was limited to a red-only display.