From the options screen, go to the Hats section and select 'Enter your code', then input the following codes to unlock all of the secret hats for Snoopy! (For those that don't know the characters, use the following key and match the character to the color of their background: Snoopy - Blue Marcy - Red Woodstock - Brown Charlie B. - Yellow Pigpen - Green Linus - Cyan Lucy - Dark Blue Sally - Pink Schrodinger - Purple