Someone thought it was a good idea to throw in a Wii in a Game Boy Color so he simply did. The IPS screen is 3.5 inches and runs 480p. However, it does not support the controls' pointing functions as it does not have a sensor in it. So only games that do not need to use controls can be played.
But as you know, the Wii is backwards compatible with the GameCube, which means that it can also play a lot of nice GameCube games and other Nintendo classics via Virtual Console.