Super Mario Spikers (cancelled Wii volleyball-wrestling sports game; 2007)
Super Mario Spikers was a game that Next Level Games, who previously made Super Mario Strikers for the Nintendo GameCube in 2005 and Mario Strikers Charged for the Wii in 2007, had pitched to Nintendo in the early years of the Wii after they gave them more budget and creative direction due to how successful the Strikers games were.
Originally, it was simply going to be a Mario-themed volleyball game titled Mario Volleyball, likely to fit in with other Mario spinoff names (Mario Golf, Mario Kart, etc.). As development went on, however, the team felt compelled to incorporate wrestling elements to their game, possibly inspired by their then-recent work on WWE Titans Parts Unknown, and eventually retitled the game to Super Mario Spikers. Eventually, they had enough material made to show it to Nintendo, including concept art, animations, and even a playable prototype. Ultimately, upon seeing the content, Nintendo rejected it due to the game's violence going against their code of honor, and production was promptly stopped.
During NLG's showing of the game to Nintendo, they had a fairly functional prototype of the game to show to them. No footage of the prototype has been found online nor has a dump of it been leaked, and it's unknown if anyone at Nintendo or NLG still has a copy of it.