To unlock the Control Pad Launcher, you must get at least a Gold medal in every quest.
Rotate the launcher
Launch a marble
Switch between multiple launchers
The option to select the STAFF button on the options menu becomes accessable after playing through & beating every stage in Quest mode. It doesn't matter if you score a gold, silver, or bronze metal on the stages. All you have to do is manage to beat them all. After completing the final boss in Quest mode, the game will make you play the Staff game once, then once it's done, you'll be able to accesss it and re-play it anytime you want!