When you are fighting Bowser, he will those these spikey balls at you. Then, when you have the ball, fire it at Bowser. Then, the ghost that trapped Mario in the painting will come out of his 'coustume'. You have you suck him up in your vacume. Once you have sucked part of him in the vacume, he will go back into his Bowser coustume and do the same thing again. Keep doing the same thing until that ghost has no life left. Then you will win the game!