Letter tiles are large blue square-shaped tiles with gold decorations on the edges. Each tile has a letter in the centre, which can be either an "S," "P," "O," "N," "G," "E," or "B." Each area in the game has a set of nine letter tiles, and collecting them all spells the name "SpongeBob."
Letter tiles are rewards for completing certain tasks in an area, and all nine of them are needed to find the area's treasure. In total, 63 letter tiles need to be collected in order to complete the game.
By pausing the game, the player can check a To-Do List that lists all the letter tiles and how to get them. Below are the aforementioned lists.
Note: Tasks marked with "*" can only be completed by returning to the area after progressing through the game.
Downtown Bikini Bottom and Chum World are the only worlds where SpongeBob can't collect all the letter tiles on his first visit, as some of the letter tiles can only be collected after progressing through the game.
The last two tiles in a set are nearly always obtained by collecting a certain number of doubloons and jellyfish/insects. The one exception is Jellyfish Fields, which lacks the jellyfish-related letter tile.