Was the tech for motion controls up to Wii era standards by 2001? For the sake of the scenario, I'll assume that they were.
Miis would not necessarily have been a part of the GC-Wii ecosystem, since the project that became Miis started as a project for the DS. I expect that a lot of games like Wii Sports would have suffered as a result.
A lot of GameCube era games would likely have looked very different. SSB Melee is so closely tied to the GameCube controller, I can't imagine that turning out as well as IRL.Luigi's Mansion likely would have tried to do something like tying the flashlight to the Wiimote, completely changing the game's perspective. Games like Wind Waker and Star Fox Adventures would have tied combat to Wiimote waggling. Metroid Prime would have been even more mindblowing with pointer controls.







