Connect the Characters
From the Super Mario Wiki
The player sees four heads of the characters at the top of the screen and the bodies of them in the bottom. The goal of the minigame is to match each falling head to the correct body, drawing with the Stylus horizontal lines between the four main vertical ones, creating different paths. Each head takes every horizontal path it comes to. Once the player has finished making the paths for the heads to match on their respective body, he or she can press the GO! button on the bottom to see them sliding down to the bodies. As the game progresses, the paths drawn previously remains, making it harder to properly match the pieces. After five rounds, the lines are cleared away, and the difficulty rises. Other characters' heads are added as the game goes on, starting with just Mario and Yoshi, but adding Luigi and Wario in later levels.
 In-Game Instructions
Draw lines to match the character's heads to their bodies. Press "GO!" when you're finished to see how you fared!