Shigeru Miyamoto has explained that the leaked Star Fox Wii U has been in development at Nintendo headquarters for quite some time. The game was originally developed for Wii, but they decided to bring the game to Nintendo’s latest home console, Wii U. The reason they decided on Wii U was because Miyamoto believed that the project worked best using the GamePad.
We originally began working with Star Fox back on Wii, and we had a small group of people experimenting with it for many years, maybe about six years, but we didn’t find an idea that really brought that together for the Wii. So instead we moved experimentation to the Wii U using some of the same assets. It’s been maybe 6 to 10 months that we’ve been experimenting with it.