At the main menu, select your Mii and it will do different things. If you select its right arm, it will give you a thumbs up. If you select its left arm, it will wave. If you select its head, it will shake it. If you select its torso, it will jump. If you select its right leg, it will lift it up along with its hands. If you select its left leg, it will act as if it is about to fall.

After you first reach the finish line on Stampede, go to the Wii Play main menu. In the background, you should see other Miis that are on your Wii walk across the screen. They may do the things that the Mii you are using does when you click on different parts of the body. A few might fly across with a swimming-like motion. The only "click action" the background Miis do not do is the one where their eyes temporarily become round.