Takeshi's Challenge (lost prototype of Famicom game; 1986)
Takeshi's Challenge is an infamous 1986 Famicom game that was originally meant to be based on the Japanese gameshow Takeshi's Castle (known as MXC in United States) and is known around the world for its hard difficulty.
Very little information is known about the original project: Takeshi's Castle was in development before Kitano contacted the game designers about ideas for a new game.
The game's main defining gimmick would have been being able to exert violence on all characters (similar to the later Grand Theft Auto series) but many of Kitano's ideas were scrapped due to the Famicom game system's limitations, or because the content was not suitable for young children. In the final product, some of this "violence potential" remains, but it is limited to a few characters and options.
Game adaptations of Takeshi's Castle, Takeshi no Sengoku Fuunji, Family Trainer Totsugeki! Fuun Takeshijo and its sequel Family Trainer: Fuuun! Takeshi Jou 2, were later released on the Famicom in between 1987 and 1988.
It is unknown if any work from the original version of Takeshi's Challenge is still around.