A purple block after the halfway point flag leads to a room with two Koopas. Kill the Koopas to reveal the Green Star. After you blast through the long clear pipe, jump on the ? blocks to discover ...

This aquarium type level introduces Koopa Troopas and the Ground Pound move. This enemy cannot be eaten and turned into an Egg. However, you can put the Koopa Troopa into your mouth and then spit out ...