An easy way to kill the first boss is to wait until you see an opening in his shield. Once you see an opening use the walls to climb over that spot and shoot at his shield. Repeat this process until you manage to defeat him.
Go to the Extras option at the main menu. Choose the Cheat Codes option. The screen will then show four boxes with pictures in them. Line up the pictures in the correct order by scrolling through them, then choose Enter Code to activate the code you wish to enter.
Enter Baseball, Baseball, Baseball, Shirt as a code.
Enter Baseball, Bat, Bat, Baseball as a code to unlock Big hair.
To unlock paper pants enter Bat, Bat, Hat, Hat as a code.
To unlock underwear enter Hat, Hat, Shirt, Shirt as a code.
To unlock Sunglasses enter Glove, Glove, Helmet, Helmet as a code.
Enter Hat, Glove, Glove, Hat as a code to unlock big feet.
Enter Hat, Helmet, Helmet, Hat as a code to unlock big heads.
To unlock big comb enter Baseball, Bat, Bat, Baseball as a code.
Feather cloud mode
To unlcok feather cloud mode enter Bat, Shirt, Shirt, Baseball as a code.