After defeating Bowser, you will unlock the World Secrets level(s).
Each world will have a new level the 5 times harder then any level you'll normally find in that world. Once you complete all 6 secret levels, defeat Bowser one more time to unlock the second set of secret levels. To defeat Some tricky bosses
To defeat the Plant Ghost in a Pot, Just push the pot until it falls over the edge. The ghost may shoot some fire balls that home in on you, just run. Also, some Shy-Guys will try to push the pot over to your side.
Pirahna Plant boss. Just like you learned, eggs can bounce on water. Fire the eggs at the water and aim it so it will bounce and hit the Boo-Boo on the plants underside.
Hookbill the Koopa: Just shoot 4 eggs at his nose until he tips over. Jump on his belly and body slam him. Remember, body slam is done by presseing A then pressing down in mid-air. If you run out of eggs, wait until he bends over and jump on his head, He'll cough up some eggs.
Boswer mini: body slam the ground to cause a shockwave to hit him 3 times. Big Bowser: avoid the boulders that break the ground and his fireballs. Grab the flying eggs (you can only have 1 at all times) and aim carefully so the eggs fly up and land on his head. Blast him like 12 times. He will jump backwards. The eggs will only hurt him if you hit any above his chest
We have more cheats and tips for this game here, Super Mario Advance 3: Yoshi's Island cheats
Comments for this hint