Return to the
Airport
Once you've beaten the game (and saved your game), you will be able to go back
to the Airport from the very beginning. It'll cost you, though. For the price of
10 coins, a boat close to the clock tower where you find Yoshi will take you to
the Airport level.
Sunglasses and Hawaiian Shirt
Look for a man with black sunglasses in the hub world (he's at the beach, close
to the fruit stands) or in most of the other levels and talk to him. When
certain conditions are met, he'll give you a pair of sunglasses to wear.
The same guy will also give you a Hawaiian shirt but you've got to do some work
first: finish the game. If you've saved your game after you beat the last big
boss, you'll be able to get your shirt anytime you talk to this guy
