Defeating The Flying Dutchman
Dodge his attacks until he throws a lot of bombs. Pick one up, dodge the flying ghost he summons (if it hits you, SpongeBob drops the bomb), and throw the bomb at The Dutchman. Dodge his portal, then he starts his attacks over again. Repeat the bomb technique.
When the Flying Dutchman becomes whole from his ghost phase, fire a bubble at him to stop him from blowing fire. When the barrels come down from the bubble hit, activate the karate chopping ability Sandy gave you. Karate chop one of them into the Flying Dutchman before they hit the floor. Note: Doing this requires precise timing and good aim.
Downtown: Letter tile
In the Downtown section, there is a specific letter tile that must be obtained by "shooting the bolts to cross the chasm". To get this, go to the construction site and to the area past the drills to where the water and barrels are located. Make
sure you are in the Mermaid Man costume. The area is just after you get past the drills, not the location where you delivered the Krabby Patties to the foreman. Instead, run to the right where there is another man. Look to the left and you will see a glowing red object on the wall. Use your water balls to hit it. It will drop a platform. Jump to this and repeat until you get the tile.
Goo Lagoon: Letter tile B
On the to do list in Goo Lagoon, on the job where it says "To the crows nest", it really means the top of the old, junky ship wreck where you have a karate match with Larry the Lobster. Go to the part of the ship that is moving. When the pole gets low, jump on it. It will go high again and you will get a letter tile.
Jelly fishing gear costume
At the Krusty Krab, body slam the target. A tent will appear and you will have the jelly fishing gear costume.
Level Select
Pause the game. Press and hold L, R, B, X. Use the control stick and press Z to pick what level and area you want to go to from the list.
Mermaid man costume
In downtown (construction site), deliver Krabby Patties to Patrick and he will give it to you.
Midway games: Finding Plankton
Before you can get Plankton, you have to complete the Bikini Bottom, Down Town, Tree Dome, Jelly Fish Fields, and Goo Lagoon levels; and have to get all the other letter tiles at Chum World. Go to the area where the back entrance of the "Big Top" is located. You will see a black speck holding up a letter tile. That little black speck is Plankton. You will have to chase him. The best strategy for this is rolling. When you are directly behind him, jump. If you get him, you will get the letter tile . If you lose, he will yell and jump into a vent . You will then have to go back to where you started and try again. Do not try sneaking up on him from behind -- it does not work. Then, you get to go treasure hunting.
Reep blower costume
In Jelly Fish Fields, win the 100 jelly fishing contest. Your prize will be the Reep Blower costume.
Tree Dome: Running on the Hamster Wheel
Before you jump on the Hamster Wheel, change into your "Fishing Gear" costume. Then, jump on the wheel and keep jumping until the timer reaches zero.