While the technical path to playing WBFS files exists, the pursuit of "free" copyrighted games is fraught with legal and security pitfalls. The safer, more reliable, and ethical approach is to purchase a physical copy of the PAL Special Edition. This not only ensures you have a safe, malware-free file to potentially use for your own backups but also supports the developers and the gaming industry as a whole.
If you do not have a physical Wii console, the WBFS format can be read directly by the Dolphin Emulator on PC, Android, or Mac. just dance 4 special edition paldwiiwbfs free