Unlock the following cheats by entering the corresponding codes at "Bonuses" > "Cheats" > "Go Down". To enable a cheat, pause the game and select "Cheats" > "Go Down". Highlight the cheat and press X.

CHEAT FUNCTION - CHEAT CODE
Carl creates multicoloured balloons when he jumps - "BALLOONPARTY"
Carl jumps from the teeter totter lifting Russell up in the air - "CARLHEAVYWEIGHT"
Carl wears Muntz's aviator goggles - "AVIATORGOGGLES"
Russell attracts all butterflies - "BUTTERFLY"

Reach a part where you are on one vine and have to swing to another one. Go on the second vine. Instead of going forward, press A while going backwards. You should be rubbing against the vine behind you. Once you reach the bottom of the vine, he will perform a backflip and hold onto the vine. Note: this will only work with the old man, Carl.