Go to the first level that has carts that ride on the rails. If you don't have both Diddy and DK, bust the barrel to get them. Jump into the barrel and ride the cart until you get the save point barrel. Once you get the barrel, get hit by anything that will cause one of your characters to die. They will both jump into the air and as soon as they do that, push B and Y together as many times and as fast as you can. You should start floating in the air. As long as you continue to push B and Y over and over again, you will continue to float. It looks like you are jumping in the air. You can jump through the air back and forth through the level, but if you go to the very beginning where you initially start off with the cart, you will fall and die.
Submitted by: Mitchel VanRassel