Patrick Star: SpongeBob's loyal, yet lazy starfish friend. Drives a boat.
Mystery Rider: A racer who, in the end, turns out to be Sheldon J. Plankton. He always tries to think of ways to steal the Krabby Patty Formula. The reason he enters the race is so he can win the year Krabby Patties. He is an unlockable character by winning Cup 3 on Hard mode.
Tommy Pickles: A small baby with a big heart who loves to have adventures with his friends. Drives the Reptar Wagon.
Angelica Pickles: Tommy's bratty cousin who loves to make fun of Tommy and his friends. Drives her pink Cynthia car.
From Hey Arnold
Arnold: A bold football-headed kid who tries to solve the problems of every day life. Drives a cardboard soapbox kart.
Helga Pataki: A girl who picks on Arnold, but secretly has a crush on him. Like Arnold, she drives a cardboard soapbox kart.
From The Wild Thornberrys
Eliza Thornberry: A girl with the ability to talk to animals. Drives a miniature version of her family's Comvee.
Darwin Thornberry: A chimp who is Eliza's best friend. Drives a Jungle Jeep.
CatDog: A cat and dog formed together. Drive the minivan from the episode Fred the Flying Fish.
From The Angry Beavers
Norbert and Daggett: Two hip and happenin' beaver brothers. Drive together in a little log. In the Game Boy Color version, they drive separate and their names are labeled vice versa.
From Aaahh!!! Real Monsters
Ickis: A cowardly, rabbit eared monster with the great ability of looming. Drives a beetle-shaped car.
From The Ren and Stimpy Show
Stimpy: A dimwitted feline with a passion for Gritty Kitty, pre-chewed gum and his pal, Ren Hoek. Drives a litter box.
Bikini Bottom Blowout
Gritty City Circuit
There is an updated version of the game called Nicktoons Winners Cup Racing which has more "modern" Nicktoons characters such as Daniel "Danny" Fenton from Danny Phantom. The even newer version is called Nicktoons Nitro for the arcade.
This is the first game SpongeBob has appeared in.
This is the first NickToons related game for the PlayStation.
One of the dialogue the mystery rider says is "Come back here, you swine!"  which is reused from the episode "Plankton!" However, the word swine is offensive in some countries.