Jump on the flagpole at the end of the indicated World when the last two digits of the timer displays the listed number. The original NES sound of a world being cleared, fireworks, and a rainbow will confirm success. Return to the world map, and an entrance to the corresponding rainbow level will appear at the entry point of each world.

World 1: Timer ends in "11"
World 2: Timer ends in "22"
World 3: Timer ends in "33"
World 4: Timer ends in "44"
World 5: Timer ends in "55"
World 6: Timer ends in "66"
Flower World : Timer ends in "88"
Mushroom World: Timer ends in "77"
Star World: Timer ends in "99"