That really sucks. When you download it, at the initial screen, it should have icons for the respective controllers you can use (ie...gamecube, wii-mote, or classic controller. This is BEFORE you confirm the download. If it showed being able to use the gamecube controller, you should be able to. My advice would be to turn off the Wii, re-plug the gamecube controllers, then turn the system back on and try.