Instructions
Play through the level in it's entirety, listening to all of the tutorials. At the end, several "prize bubbles" will drop. Collect the prizes and then step on the red button to end the level.
Restart the level. When the "Self-destruction" instructions begin, look for a shoe-shaped cardboard cutout.
Open your "Pop-iy" with the square button. Select the "Rainbow Shoe" sticker from the "Switches" list and then paste the sticker on the cardboard cutout. A bird will come down from the top of the screen. Grab onto it with the R1 button and let it fly you out of the "Self-destruction" tutorial. Then complete the level (without dying) to earn the "Ace" distinction.