Get 100 points on each of the eight stages (except the secret stages) in a World for a total of 800 points. To do this, you must collect 20 red coins, 5 flowers, and 30 stars.
Extra 1 level: Get 800 points for World 1.
Extra 2 level: Get 800 points for World 2.
Extra 3 level: Get 800 points for World 3.
Extra 4 level: Get 800 points for World 4.
Extra 5 level: Get 800 points for World 5.