The SpongeBob SquarePants Movie 2 was the cancelled 2014 sequel to the 2004 film "The SpongeBob SquarePants Movie", It was going to take place after the first film, And The Sequel was gonna be about SpongeBob and the Gang going to Alantis to save Patrick who has been kidnapped by Monster Starfish.
It was later reworked into "Sponge Out Of Water" in 2015 Instead.