Super Mario 128 · Nintendo GameCube · Build: August 2000 · Discovered: 2000 · Public Trade Show Demo
Shown at Nintendo Space World 2000, Super Mario 128 put 128 Marios on screen at once and was never released as a game. Its ideas ended up scattered across Pikmin, Metroid Prime, Twilight Princess and Super Mario Galaxy.
At Nintendo Space World in August 2000, Nintendo demonstrated the raw capability of the forthcoming GameCube with a technical showcase called Super Mario 128. It did what its name promised: 128 individually simulated Marios stood on a circular platform, marched about, assembled themselves into a giant Mario mosaic, and deformed the terrain beneath them — which could be raised, lowered, and at one point folded into a pizza. It was a physics and AI stress test wearing a Mario costume, and Shigeru Miyamoto said as much at the time. The gaming press did not listen. For six years "Super Mario 128" was reported as an imminent Mario sequel, and its non-appearance became one of the era's great vapourware sagas. The name had form: Nintendo had already used it internally in 1997 for a cancelled 64DD follow-up to Super Mario 64. Miyamoto finally confirmed the project's cancellation in 2006, and at GDC 2007 explained where it had gone — not into a game, but into several. The crowd-AI work resurfaced as Pikmin; the walk-on-a-sphere geometry became the defining mechanic of Super Mario Galaxy. Nothing playable has ever leaked.
The confusion was structural. Nintendo needed to prove the GameCube could handle vastly more simultaneous simulation than the N64, and the most legible way to prove that to a room full of journalists was to fill the screen with a character everyone recognised. But putting Mario in a tech demo, in 2000, and calling it Super Mario 128 was effectively announcing a game — regardless of what was said from the podium.
For the next six years, every Nintendo press event carried the question. Preview sections listed it. Rumour columns speculated about its engine. The gap between what Nintendo had shown and what the audience believed it had been shown widened until the demo had acquired an entirely fictional second life as a delayed, troubled, endlessly-rumoured Mario sequel that had never existed in the first place.
Miyamoto's GDC 2007 keynote reframed the whole saga. Super Mario 128 was not a game that failed; it was research that succeeded, and whose results were harvested into other products. The problem of making 128 autonomous agents behave as a coherent, commandable crowd is, in the end, the problem of Pikmin — and Pikmin shipped in 2001, a year after the demo. The problem of keeping a character correctly oriented while walking around the outside of a curved surface is the problem of Super Mario Galaxy, which shipped in 2007.
Read that way, the demo is one of the most productive pieces of unreleased software in Nintendo's history. It never became a Mario game, but it is a load-bearing ancestor of at least four shipped titles across two console generations. The vapourware everyone was waiting for had already been delivered — just under different names.