There was originally going to be a Squidward robot battle. Although this never happened, there is concept art that you can unlock and one of the pieces depicts what the battle would've been like. The robot Squidward would've had big tentacles that would attack you and you'd have to press switches which would drop rocks on top of them. The robot battle did however get ported on the Game Boy Advanced version of the game. The rehydrated version of the game does feature the Squidward robot battle.
In the Goo Lagoon level, there is a beach with sand castles. One of the sand castles is actually a sand version of an Atari 2600 controller.
All of the voice actors from the show returned to voice their characters in this game, except Clancy Brown and Ernest Borgnine, who voice Mr. Krabs and Mermaid Man respectively. Joe Whyte voices these 2 characters instead.
The fire that the "Tubelets" enemy produces changes color if the console's date is currently on one of the following holidays:
January 1st/New Years (Rainbow-patterned fire)
March 17th/St. Patrick's Day (Green fire)
April 1st/April Fool's Day (Pink fire)
July 4th/Independence Day (Red, white and blue pattern)
October 31st/Halloween (Orange color)
Clancy Brown was unable to voice Mr. Krabs in this game because he was busy lending his voice in Jak II.