SpongeBob SquarePants, Kitty Katswell, Sheldon J. Plankton, Chum Chum, and Monkey were always in this game, everyone else was added at different days.
Classic SpongeBob is a selectable character from the prequel game, Super Brawl.
Also SpongeBob, Patrick, Sheen, Timmy Turner, Fanboy, Otis, Rico, King Julien, Aang, Danny Phantom, Doctor Blowhole, and Bessie Higgenbottom are the only playable Super Brawl, Super Brawl Summer, and Super Fall Brawl characters to return in this game.
Chum Chum is in those games, but not as a playable character, he was in the background when you play as Fanboy.
When Classic SpongeBob became a playable character in this game, the Krusty Krab arena was originally called "Classic SpongeBob Level." This was later changed to its actual name.
Patrick was not a playable character in this game until June 19, 2011.