The Flintstones in Viva Rock Vegas (lost builds of cancelled GameCube port of racing game; early 2000s)
From The Lost Media Wiki
Box art of the GameCube version
Status: Lost
The Flintstones in Viva Rock Vegas was a Europe-exclusive racing game based on the film of the same name. The game was originally developed for Dreamcast, but cancelled and later released on PlayStation 2. However, a GameCube version is mentioned on various sites, such as IGN, GameFAQs, and even an Amazon listing, albeit unavailable.