Things You'll Need
Instructions
Complete the princess sliding course on the first floor to get the first secret star. Then press the "Start" button and choose to play the course over again. Complete it in less than 20.9 seconds to get the second star.
Go to the entrance located near the wall of the picture for the third stage on the first floor. Do a backflip to get up to the entrance. Collect all eight red coins in the swimming course and you'll receive the third star.
Go to the basement after have collected 20 stars and grab the yellow rabbit that is hopping around by pressing your "B" button and you will get the fourth secret star. After you get 50 stars, go back to the basement again catch the rabbit again to get the fifth star.
Go to the third floor and enter the entrance on the opposite wall of the 15th stage. Do a backflip to enter the special course. Collect the eight red coins in the flying course to obtain the sixth star.
Find the three Miss Mushrooms to receive the seventh, eighth and ninth secret stars. Go to the pool near the entrance of the sixth stage in the basement to find the first Miss Mushroom. Go to the second floor toward the opposite side of the 12th stage to find the second Miss Mushroom, and go to the clock on the third floor to find the third Miss Mushroom.
Complete the red, green and blue switch stages. Get eight red coins in each stage to receive stars 10, 11 and 12. Get all eight red coins in each of Bowser's stages, which include the Dark World stage, Fire Sea stage and Sky stage. You'll then get the last three secret stars.