SpongeBob's Atlantis SquarePantis is a 2007 SpongeBob SquarePants video game based on the TV special "Atlantis SquarePantis", published by THQ and developed by Blitz Games (for the PS2 and Wii versions) and Altron (for the NDS and GBA versions). This is also the last game for the PS2 and GBA.
In the beginning of the game, SpongeBob and Patrick are blowing bubbles. They blow one that is too large and they get trapped inside, taking them to a cave. In the cave, they discover parts of the Atlantean Amulet. After finding all ten pieces, the cave begins to collapse and they must escape. After leaving the cave, the two go to Bikini Bottom and show the Amulet to Squidward at the museum. He realizes that by finding the Amulet, they are able to go to Atlantis.
They want to take Mr. Krabs, who agrees, but makes SpongeBob and Patrick find his golden spatula first. After finding it, they try to get Sandy to come with them, who agrees under the condition that SpongeBob and Patrick defeat her in a karate match. After defeating Sandy, they head into the bus and fly to Atlantis, but run out of song fuel. The bus then crashes.
They discover that they are in the lost continent of Mu. The leader of Mu tells them that they can find sheet music for Squidward to play there, but they need to find the red and blue jewels to be able to access it in the ruins of Mu. They find both jewels and fight a boss for the sheet music, but they discover it is too dirty.
So they head into the volcano to find a sacred fire flower that can make the music readable. Upon finding it, Squidward's clarinet has been stolen by a giant jellyfish, but they manage to recover it. Squidward plays the sheet music, providing the song fuel needed to reach Atlantis.
After reaching Atlantis, Lord Royal Highness lets them explore it. They travel through a treasure room, a science lab, a music room, and an industrial factory before they finally reach the world's oldest living bubble.
Unfortunately, SpongeBob and Patrick pop it and the Atlanteans turn on them, forcing the two to have to escape quickly. After fighting through the Atlantean guards, they reach the courtyard of Atlantis, where Plankton pops out. They destroy Plankton's tank and return home to Bikini Bottom.