Super Mario Gravity is a Super Mario Galaxy 2 mod featuring brand new galaxies. This mod will feature over 30 galaxies and will be playable legally on any homebrew-enabled Wii or Wii U console.
Project X is an unreleased spin-off game set in the "bad ending" part of the The Legend of Zelda timeline. It would have explained the origin of the Master Sword and featured Sheik as the main protagonist rather than Link.
The game became known through the concept art being found on the internet through the original artist's web page, which was later taken down. After further research it was discovered that the game was being developed by Retro Studios as a concept, being greenlit by Nintendo to become a prototype, which didn't get approved.
The gameplay seems to have involved an arcade-like whack-a-mole-inspired movement with the Wii Remote to fight against enemies (with wolves being the first ones programmed in the game).
Spider-Man 4 is an unreleased Wii game developed by Eurocom. The game was intended to be a tie-in game for the movie Spider-Man 4, however it was cancelled due to the cancellation of the movie.
The game has since been released online in 2020, after a prototype was found on a RVT-H Wii development kit.
Dance Dance Revolution Mario Mix 2 is a cancelled sequel of Dance Dance Revolution Mario Mix that was planned for the Nintendo Wii. It's existence was confirmed when documents relating to the Wii hardware were leaked as a part of the July 2021 batch of the gigaleaks. It's currently unknown if development ever officially started.
Koopa Troopa Forest is an unreleased Mario game that was made to showcase how the pointer controls for the Wii would work. The game's existence was unknown until July 2021, when documents about the development of the Wii were leaked as a part of the Gigaleaks.
Sword of Legendia was a video game announced in 2006 by Namco Bandai Games, for the Wii. Despite the title's similarity to the Namco 2005 PlayStation 2 role-playing video game title, Tales of Legendia, it was confirmed by producer Tsutomu Gouda that it wasn't part of the Tales series. In a Japan Expo 2011 interview, the game was revealed to have been cancelled.
Super Mario Spikers is the name of a canceled volleyball-wrestling hybrid game that was to be developed by Next Level Games, the same studio that created Super Mario Strikers for the Nintendo GameCube and Mario Strikers Charged for the Wii.
Sonic Duel is a Super Smash Bros. Brawl mod, which transforms the well known Nintendo game to a almost completely different title. Removing all (but one) original characters, it replaces them with various characters that have appeared in the Sonic the Hedgehog games. With various maps and soundtracks from the world of the blue speedster, this mod takes Brawl to a completely different league.