Level 2
This is a grassy area. The double pipe to the right can be good use. When using the Super leaf goombas coming out of the pipe can be stomped on repeatedly to get 1-ups. As long as you don't touch the ground. Further on you will find a pipe in the air with a piranha plant in it. Hit the switch in the block underneath the pipe to turn the blocks into coins. You can jump into the pipe. Keep going and you'll reach the exit.
Infinite Lives
Being such a short level there is only one good use for it, infinite lives. Make sure you have used a Super Leaf, and are a Raccoon Mario. Find the location pictured at left. The winged ParaGoombas are the key to this trick. Stay near the Goomba tube that keeps producing them sideways. Jump on the ParaGoomba to remove his wings, while using your tail to float through the air and continue stomping and floating back down. The ParaGoomba will start back up the hill on the right and grow his wings back. As long as you keep him alive, stay near the tube, and float back down, you can spend 1 life to get 50 lives.