The player plays as one of the six main characters (one of them is inside a robot however). When the player starts the game, he or she has an option of choosing versus, story, and practice mode. Versus mode is when the player connects to the server and fights with online players (this only works on the Nick.com version). Story mode is when one can fight against all the other characters. Practice mode is when one can do a single fight against any character and choose what location the player wants to brawl in. Once the player starts the fight they use the arrow keys to move. Press the up key to jump. Press Z for special attack and X for super attack once the meter is full. Press the space bar to attack and pick up items.
The player and his/her opponent are trying to knock each other out! The player or his/her opponent will lose a life if the player or his/her opponent is knocked out of the screen or if the player or his/her opponent falls too far. The player has three floating platforms to jump on if necessary. There are also boxes that appear and give the player various power-ups to use against the player's opponent. The game ends when the player or his/her opponent is knocked out and loses all four lives. There are also outfits the player can choose for his/her character.
The characters have various phrases and words that are either heard or written in speech bubbles during storymode. The Dialogue is reused from various SpongeBob episodes. Some have been slightly changed from the original dialogue.
File:Bikini Bottom Brawlers Game Over.pngScrapped "Game Over" screen?In a video found here, while the Nick gamer was advertising this game before it was released, some early gameplay is seen which is not seen in the final version. Example: There was originally a "Game Over" screen. However, in the final version, it is changed to "You Lose."
Bubble Bass is briefly seen on the Bass Vegas sign.
There is a very minor glitch in the game where the player can lose two lives at once instead usually losing one life.
The glove power-up in this game is from Glove World.