The Keeper of the Lake
When the player completes either The Shallow End or Treacherous Currents, a cutscene plays inside the S.S. Dolphin II where the ship announces that it managed to found both a large treasure and a large beast. It advises Captain Olimar to carefully explore the next area. After the treasure is collected, the ship reveals that it found a new sector, the Sparkling Labyrinth, and makes notice of the fact that it takes place underground, and has a lot of crystals.
The area starts in a room out in the open, and its walls are too tall to climb out of. There is a hole in the floor leading to an underground lake, however. The lake is roughly 10 screens wide, and 7 and a half screens deep.
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