Liberado TechDemo X / NesGlider (SNES - Prototype)

The small british developer Argonaut Software had Nintendo attention when in the early nineties they defeated the copyright protection mechanism on the popular Game Boy console and developed a 3D engine for it, a feat thought impossible even by Nintendo itself.
Nintendo then hired these worthy programmers to work on polygonal games on their systems.
They did a 3D demo codenamed NesGlider for the aging NES and then ported it on the then brand new SNES.
The performance weren't good enough so Argonaut suggested to create a chip to handle the taxing math calculations.
Nintendo accepted the idea and let Argonaut to develop a RISC based microprocessor codenamed MARIO that later was known to the public as the Super FX.
Led by Shigeru Miyamoto and by Argonaut tech expertise Nintendo created the much beloved Star Fox in 1993 which was the first polygonal based game to have sold million of units on console.

This is what Jez San, Argonaut Software founder, recollected in a recent interview:
"We'd done a demo of 'NesGlider' in 3D running on the NES.
They gave us a SNES to play with - long before its release - and we ported it to that. We showed it to them and said this was pretty much the best 3D their console could produce, and that they hadn't designed the SNES with 3D games in mind. Then I suggested that if they wanted better, they should let us design a 3D chip for them. We had never designed a 3D chip before, but we had done some hardware so it wasn't a completely bullshit idea. I promised them that we could design a chip that would accelerate the 3D graphics by ten times what their wimpy CPU could do."

This is a video of the X/NesGlider prototype, courtesy of hidden-palace.org, which date back to May 1991.
As you can see in the demo you can shot laser or a more powerful bomb.
You can move freely in a 3D field reminescent of the first Star Fox level (those white points!) and blast the enemy tanks.
Hitting the start button you can change from the "tank" mode to the "walker" mode and viceversa.