If you do not own a Wii U console, the open-source emulator is the gold standard for playing Wii U games on Windows, Linux, or Steam Deck.
Wii U WUP files are a specific format used to install games, updates, and DLC directly onto a modded console's home menu . Unlike formats used for PC emulation, WUP files are designed to be "packed" and installable to internal storage (NAND) or an external USB drive. Essential Tools for WUP Files
If you are looking to experience these games, here is how the landscape looks: On the Console: You need a modded Wii U to use the ConsoleMods Guide for WUP installation. If you aren't using the original hardware, the Cemu Emulator