At the main menu, tap "Credits" on the bottom right. You start a mini-game where you play as a roller trolley (the little creatures that spin on the roller coaster in between mini games), using your head. Collect the letters of the names of the staff that worked on the game, while avoiding "Space Jellyfish". Alternately, you can cheat by using your hand. You must first let the face reader read your face before you do this, however.