At the menu with the "New Game" and "Load Game" options, press Y(3), X(2), B, X, Y, B, X, Y, X, Y, X, Y, B, Y(2). If you entered the code correctly, the word "Cheat" will appear. Go to the stage/level selection screen and press Start. You will find a new "Cheats" option. Select it to find options to unlock all levels and some cheats labeled as "?".
During the Submarine level, there is a pipes puzzle you must go through. As soon as you get into the room with the puzzle, look at the back wall right behind the door to find the solution to the puzzle.
Whenever you are trying to solve a slide puzzle, its best to start from the top first. You can keep sliding and solving the puzzle from left or right as you work your way down from the top.
Going though all the bubble rings, putting the colored pebbles in the correct colored holes, bouncing on all the things that bounce, winning the races, and destroying all enemies will earn you Gold Starfish towards bonus levels. Note: There are some timed levels and timed races; be as quick as possible.
The little blue krill will keep you from getting hurt. Collect as many as you can. The krill only protect you from things such as pufferfish and eels, but not from swift currents or mines.
To keep up with Dory, grab all the bubble rings.
On the level 7 (the Submarine), if you see an ''!'' over Dory's head, it indicates you should move or Bruce will catch you. To keep away from Bruce keep rotating the Analog-stick.
When the diver is after you, he will always try to grab you in the same few locations. Learn where these are and avoid them.
When you complete a level or are at the middle of a level, you will see an FMV sequence from the movie Finding Nemo.