Select "Bonuses" at the main menu. Then select "Cheats", go down, then enter the following passwords. To enable the cheats, press Start to pause game play, select "Cheats", go down, then press X to activate a cheat.

Carl creates multicoloured balloons when he jumps
Enter BALLOONPARTY as a code.

Carl jumps from the teeter totter to lift Russell end up in the air
Enter CARLHEAVYWEIGHT as a code.

Carl wears Muntz's aviator goggles
Enter AVIATORGOGGLES as a code.

Russell attracts all butterflies
Enter BUTTERFLY as a code.