At the title screen (where it says "press Start"), press the X button to make a beetle appear. Once the insect is on the screen, you can use left and right on the C-Stick to turn it and forward to move. If you move the bug into the Pikmin that make up the logo, they will "interact" with the bug.
Press Y to make a Chappie appear. You can move it around the same way and press Z to make it eat Pikmin. To get rid of the creatures, press the L button.
Press R to make the Pikmin run around the screen and then rearrange themselves to form the word "Nintendo."