Nicktoons Racing focuses on engaging players in go-kart racing through various Nicktoons-themed circuit tracks in a variety of different modes, similar to the Mario Kart series. The game features a wide selection of playable characters from various 1990's Nicktoons. The game offers an Easy, Medium, and Hard difficulty for the gameplay (with the game allowing you to unlock subsequently harder modes by accomplishing the last difficulty fully in Cups). The game also has a multiplayer option and can be played with a second player via split-screen utilization (multiplayer is available to all versions of the game except the Game Boy Color).
Each track features power-up presents that allow the player to gain advantages against their fellow racers in the form of various weapons and obstructions, as well as small orbs that a racer can collect and utilize to get a short-term speed boost. Each track also contains a variety of alternate routes and shortcuts that allow the various racers to shorten their laps (the harder the difficulty selected by the player, the more likely the NPCs are to utilize the shortcuts).
Cups
The primary mode for the racing gameplay. This mode allows the player(s) to take control of one of the Nicktoon racers and compete in a series of 4 races in the form of a Cup. There are 3 Cups and the second and third have to be unlocked by beating the previous Cup series. This is the mode required to beat the game's main story, unlock all the tracks for other modes of play, unlock The Mystery Rider as a playable kart, and the bonus minigames.
Time Trial (Single Player only)
A mode that can be used by the player to test their speed ability on each unlocked track. After finishing your first lap, a ghost racer will appear and perform the lap as the player did it on previous lap.
Race for Fun (Single Player only)
A mode that allows the player(s) to race a single track without competing in a Cup. The player progressively earns random collectible rewards for a trophy shelf the more races they participate at in a row and win.
Verses (Multiplayer only)
A mode that is generally the same as Race for Fun, but for two players instead. This mode does not feature collectibles.
Relay
A mode that allows the player(s) to pick three characters and race them in a 3-lap relay where each character performs one lap before tagging in the next racer. If the player hits their next racer directly, they get an initial speed boost for their next lap.
Bonus Levels
Besides the main racing tracks, the game also has a single-player and multiplayer specific bonus minigame that you unlock as you play-through and beat all the cups in Medium and Hard Mode.
For single-player (Medium Mode reward), the player unlocks the Hey Arnold!-themed level Big City Clean Up in which the player is given a time trial in order to find and collect 60 of the power-up presents seen in the main racing gameplay.
For multiplayer (Hard Mode reward), the player unlocks the SpongeBob SquarePants-themed level Beach Soccer in which two players push a beach ball around a field attempting to score more goals than the other in a timed match.