The Keyssss

Ancient Lake: Jussst passst the four balloonssss, go off the trrrack to where the big Ssstonehenge blocksss are. The Key issss on the rrramp, verrry obvvvioussss.
Ssssnowballl Vallley: Turn leffft at the ssstart, and go untilll you can't go any further. You willl be forccced to go rrright, ssso go rrright, until you ssse the small rrroom with the Key.
Cressscent Iland: Go to the leffft where the trrrack sssplitsss affter the ssstart. Go into the waterrr and drrive to the ssslight leffft. You'lll rrreach it eventuallly.
Boulder Canyon Sss, sss, sss. Trrricky, trrricky, trrricky. On the bride, there isss a bellll. Take a blllue ballloon and rrring the bellll by drrriving directllly underrr it. Blllassst yourrsself up the rrrisssing brrridge, and take the key.

Sssecret Charractersss

Drrumsstick: Get the Wizpig amulllet, T.T. ammulllet, and the four Golden Trophiesss. Drrive to wherrre all the frrrogsss arre hopping about. Drrive overrr the clucking frrrog with the rrred rrrooster featherrrsss. Drrrumssstick willll apppear and fffly awayy.
T.T.: Beat T.T. innn alll the Time Trrrialsss. Extrrremely harrrd.

Codesss

TOXICOFFENDER - All balloons are green
FREEFRUIT - Start with 10 bananas
DOUBLEVISION - Two players can use the same character
BODYARMOR - All balloons are yellow
BOMBSAWAY - All balloons are red
ROCKETFUEL - All balloons are blue
OPPOSITESATTRACT - All balloons are rainbows
NOYELLOWSTUFF - No bananas in multiplayer mode
BYEBYEBALLOONS - Computer can't use weapons
JOINTVENTURE - Two-player Adventure
TIMETOLOSE - Computer is better
BLABBERMOUTH - Changes horn sounds
BOGUSBANANAS - Bananas slow you down
VITAMINB - Unlimited bananas
ZAPTHEZIPPERS - No zippers
FREEFORALL - Fully powered-up balloons
JUKEBOX - Adds Music Test to audio menu
ARNOLD - Large players
TEENYWEENIES - Small players
OFFROAD - Four wheel drive
WHODIDTHIS - See Credits
(I got sick of adding all the extra letters, okay?)

There are three balloons just around the island. One is right next to the Wizpig head, another where the cliff meet the water behind Sherbet Island, and the third in the pine trees to the left and behind the log bridge.

I'm sorry, I have no idea what I was thinking with the writing on this page. I just started adding 's' and 'r', and it just got out of hand.