You can use the cannon on the beach for a shortcut. Normally you would need to use the cannon to shoot yourself to the nearby planet to get a Fire Flower then use the Jump Star to return to the beach so that you can light the two torches to open the door on the first Star, or the three torches to make the Ice Flower appear on the second Star. However, if you get in the cannon and turn it all the way to the left as far as it will go, you will see two yellow platforms moving up and down. Watch them carefully. When the farthest platform is up, line your crosshairs up with the side of it. Then, wait until the closest platform goes back up, and fire yourself in that direction. If timed correctly, the platforms will have switched again and you will hit the side of the furthest platform and fall on the ground. You must hit the wall or you will overshoot and die. This will put you inside the "bowel" area without opening the door on the first Star. If you are on the second Star, you will not have to worry about getting the Ice Flower to cross the lake and jump the faucets. You can just proceed right and climb the poles to get to the Bubble Shooter.