Mario & Luigi: Superstar Saga Hints

It is yellow colored-bean. They can be obtained by playing the Mini-Game throughout the adventure. If you always wanted a new gizmo from Professor E. Gadd that is.

Before entering a pipe, enter it with Mini-Mario. During the Pipe-Selection Screen, the music in the previous area you were just in will stay the same. When you warp to your destination, the music in the pipe will now be the BGM until you leave the area/go into pipe while not Mini-Mario, etc

Go to the gwarhar lagoon cross section and go up.there should be a surfing part.make luigi a surfboard by smashing him.then go up,right,right right.then you should reach an island with a purple guy on it.when you find that,go up once and you should find a secret minigame.good luck