Back in the heyday of Wii homebrew, hackers developed a file system specifically to store Wii game backups on a USB hard drive. A .wbfs file is essentially a ripped copy of a Wii disc or a homebrew application packaged to look like an official title.
This is a fan-made modification . You need the original New Super Mario Bros. Wii game and a modded Wii or Wii U (vWii) to play it. super mario starshine wbfs
For years, the PC version was the only way to play. That changed when the fan community discovered how to port GameMaker games to the Nintendo Wii using custom tools like or GLuPe . Back in the heyday of Wii homebrew, hackers
: Currently, a demo is available featuring approximately 20 Shine Sprites to collect across various classic stages. You need the original New Super Mario Bros
If you are ethically concerned, play the original PC release. If you want to explore the WBFS version, do not ask for links in public forums (Rule 1 of ROMs: Do not ask for ROMs), and ensure you own a legitimate copy of Super Mario Sunshine for the GameCube or Switch as a moral token.