This cable, when used with specially designed games, allows you to connect the Game Boy Advance to the Nintendo GameCube. The features available will change depending on the game, from exchanging data or unlocking new game levels to allowing the Game Boy Advance to be used as a supplemental game screen or input device. See the game packaging and instruction booklets for details on what features are activated when using this link cable.
The first two games to use the Nintendo GameCube Game Boy Advance Cable are Sonic Adventure 2: Battle for the Nintendo GameCube and Sonic Advance for Game Boy Advance. Using the cable, you can transfer data back and forth between the games.