Instructions
Clean the game before you attempt to repair it. Sometimes the Nintendo Wii games get dirty and smudged from fingers getting all over it, and all you need to do to get the game to work again is clean it. Use a microfiber cloth that has a little bit of water on it, or some window cleaner and rub the disk gently with the cloth to remove any dirt and contamination.
Apply some rubbing alcohol to the disk and wipe it over the Nintendo Wii game. Once the disk has been completely coated allow the disk to dry. Place the game into the Nintendo Wii and see if it works.
Get some plain white toothpaste and rub it over the Nintendo Wii game to fill in scratches and nicks. Let the toothpaste dry and then rub it off with a cloth. Attempt to play the Nintendo Wii game again.
Apply a thin layer of car wax onto the Nintendo Wii game and allow it to dry. Place the game into the Nintendo Wii and play the game.