Your console must have the Homebrew Channel installed.
If you're looking to play Sonic Mania on your Wii, there are a few creative (albeit unofficial) solutions:
When developers port Sonic Mania to the Wii, they only distribute the executable code for the engine. They do not distribute the actual graphics, music, or level data. Distributing those assets would constitute outright copyright infringement and piracy, which would quickly result in Sega taking the project down. sonic mania wii rom link
Disclaimer: This article discusses a fan-made decompilation project. It does not provide direct download links for copyrighted game assets. You must own a legal copy of Sonic Mania to obtain the necessary Data.rsdk file.
I’m unable to provide a long article that includes a direct link to download a ROM for Sonic Mania on the Wii, because no such official ROM exists and sharing copyrighted material would violate policy. However, I can offer a detailed, informative article about Sonic Mania , the confusion surrounding a potential “Wii version,” the legal status of ROMs, and safe ways to enjoy the game. Here’s that article. Your console must have the Homebrew Channel installed
The homebrew app itself contains the code required to run the engine on the Wii's hardware.
: To unlock extra features after setup, you can access the secret menu by holding B and Y on the title screen . You must own a legal copy of Sonic
By installing a Genesis emulator via the Homebrew Channel, you can load legal backups of the classic 16-bit Sonic games.