The title ClayFighter 63⅓ is itself a punchline. Most Nintendo 64 games simply tacked “64” onto their names, and Interplay decided to spoof that habit by calling their game “63⅓” instead, a number that also nodded to the comedy film Naked Gun 33⅓.

The game was not originally intended for the Nintendo 64 at all. Development began for the Panasonic M2, a console that never made it to market, before the project found a new home on Nintendo’s platform.

Along the way it cycled through several working titles, including “ClayFighter 3” and later “ClayFighter Extreme.”

That Extreme name followed the project toward a planned PlayStation release, which was eventually shelved. Interplay worried that PlayStation owners would view it as a belated port rather than a legitimate release.

While most fighting games of the N64 era had moved to polygon-based graphics, ClayFighter 63⅓ took a different approach. The characters were built as physical clay sculptures, photographed incrementally through stop-motion techniques to produce the in-game animations.

The clay work was handled by Danger Productions, the same company that had collaborated on the original ClayFighter.

Hits in the game triggered little clay fragments called Spillits to fly off the characters on impact. It was the series’ lighthearted equivalent of the blood and gore that games like Mortal Kombat had made controversial.

The game offered 26 distinct battle arenas, a surprisingly generous number for a title built around comedy rather than competitive depth.

The voice cast included several well-known names from animation, among them Frank Welker, Jim Cummings, and Dan Castellaneta.

Legendary boxing announcer Michael Buffer also contributed, lending his voice to in-match commentary.

Earthworm Jim appeared on the roster as an unlockable guest character.

A character called Hobocop generated considerable attention despite never making it into the final game. He appeared in preview coverage and magazine features before being cut, and later discussion around prototypes suggested his move set relied on humor that was deemed too offensive to ship.

The updated version of the game, ClayFighter: Sculptor’s Cut, was distributed exclusively through Blockbuster as a rental. Production was reportedly limited to around 20,000 copies, a figure that has since made it one of the scarcest and most sought-after cartridges in the North American Nintendo 64 library.

Reviews at launch were largely unkind, with critics pointing to weak gameplay, poor artificial intelligence, and stiff animation as major problems. A number of those same reviewers acknowledged that the game’s sense of humor landed more often than not.

The negative reception did not prevent a devoted following from forming around it. Retro gaming communities continue to debate whether ClayFighter 63⅓ was an underappreciated oddity or simply a bad game with good jokes.