Wii U's GameCube Controller Adapter works with all games supported by the Wii Classic Controller/Pro, Wii U Pro Controller
Hot Spot Collectibles and Toys - Wii Classic Controller Adapter for PC USB
Raphnet makes an adapter cable that converts a classic controller (Wii classic, Wii classic pro, NES classic, SNES classic) into a GameCube port. If you can't stomach paying $200 for the Hori
Amazon.com: Mayflash Nintendo GameCube Controller Adapter for Wii/Wii U : Video Games
The SNES Classic & Wii Classic Pro controllers both work on Mario Maker 2 using the 8BitDo Gbros Adapter, both have ideal dpads and feel right at home : r/NintendoSwitch
Classic controller to Gamecube Wii adapter 140cm Calble Updateable firmware Game | eBay
USB Wii Classic Controller : 14 Steps - Instructables
Sir Norzman on Twitter: "Got the @8BitDo GBros. Adapter. So far it works pretty good. Really nice to be able to use my Wii Classic Controller with my Nintendo Switch https://t.co/ebwMlvApGM" /