Level select:
Hold L1 + L2 + R1 + R2 and press Up(2), Down(2), Triangle, X(2) at the title screen.

Unlimited air:
Hold L1 + L2 + R1 + R2 and press Square(2), Triangle, X, Circle at the title screen.

Unlimited health:
Hold L1 + L2 + R1 + R2 and press Triangle, X(2), Up(2), Down at the title screen.

All Vitalits:
Hold L1 + L2 + R1 + R2 and press X(2), Circle(2), X, Circle, Up, Down(2) at the title screen.

Swim with a group:
Hold L1 + L2 + R1 + R2 and press X, Up, X, Down, X, Triangle at the title screen.

Dolphin Soccer:
Go to the Powers Of Levitation level and find your way to the room where the clan General (the dolphin that has the inspection) is located. Swim through the side of the wall that moves like Jello. On the floor near one of the orange lights is a soccer ball. Get it, then go to the level selection screen. An option for the Dolphin Soccer mini-game will appear at the bottom of the list.

Bonus levels:
Successfully complete the game under the hard difficulty setting. The Up & Down level will shimmer, and you can now access both 2D bonus levels. 

Passage From Genesis level:
As you start the Up & Down level, swim around the cavern until you find the Info Crystal. Below it is a hole that leads downward. The current is too strong -- you cannot swim down it. Look for the boulder just right outside the alcove where the hole is located. Push it into the hole and stay directly behind it. You will enter a room with four stone pegs. Above those pegs is the power of Sonar. Get the Sonar and use it in the small opening of the pegs. A little light should appear. Quickly light up all four and a door below will open to the 2D level. 

Pathways From Nowhere level:
After you make your way up the geyser, you will find a big ring with a spot of light in the middle. In that same area are many power jewels. Find them and bring them to the ring. Two are above the water, one is under the stone shack-like thing, and the rest are around the other side of the pool. After you have collected all of them. it will open the way to the bonus area. 

Vitalits:

Aquamarine Bay:
1: Win the Find The Fish challenge. After talking to the coach, a Vitalit will appear above the ocean surface.
2: In front of the waterfall above the surface.
3: Floating under the stone archway.
4: Atop a huge rock near the whales. Gather a lot of speed and charge at the surface, shooting over the rock. (very difficult) 
5: Hanging near the branches of the palm tree, on the opposite side of the floating logs. 

Perils Of The Coral Reef:
1: Win the race with the two dolphins, and they will make a Vitalit appear above the surface of the pool.
2: Find the dolphin who is searching for his brother. It is stashed in the lower right corner of this area.
3: In the Great White Pool near some coral, between two caves. 
4: After you defeat the Great White, a Vitalit will appear above the surface near the waterfall.
5: From the Great White pool, take the dark tunnel (using 
Glow Fish to light the way) to discover the last Vitalit. 

Trial Without Error:
1: Near where you find the baby dolphin in the dark cave. 
2: When you save all of the baby dolphins the mother will make another Vitalit appear.
3: Just before the pool of sharks, you will find the Vitalit just past the tunnel exit.
4: Near the power of Vigor.
5: Near the Octopus in his subterranean cave. 

Four Ways Of Mystery:
1: In the dead end to the left of the White Crystal.
2: Floating above the pool with the recluse dolphin who teaches you the Song of the Ray.
3: In the pool with the Giant Manta Ray (without the dolphin). 
4: In the blue crystal path, take a right at the crystal, then follow the path to a crossroads. Head right again here to get the Vitalit.
5: Once you learn Power Of Sonar, use it on the big rock on the roof of the main pool to get the final Vitalit. 

Up And Down:
1: One of the alcoves of the main chamber contains a Vitalit. 
2-4: Three Vitalits are to be collected as you follow the flow of the geyser up.
5: Floating above the waterfall. 

Roaring Forces:
1: In the start chamber, leap over the floating boards.
2: Stashed in the rocks near the waterfall.
3: Once you pass the dolphin puzzle, swim through the rocks and look up to find the third Vitalit.
4: Just before the entrance to the Morphing pool, you will find a Vitalit between the walls.
5: Next to the exit. 

Atlantis Lost:
1: Leap into the air from the starting point.
2: Nestled in the reeds on the left side of the pool.
3: On the far end of the pool next to the Sonar Power-up is a pile of rocks. Blast it with Sonar.
4: Facing the main temple from the accelerator rings, the building just ahead and to the right contains a Vitalit.
5: The main temple houses a Vitalit near its domed ceiling. 

Shrine Of Controversy:
1: In the Circle Shrine.
2: Near the Wheel Of Pain you will see an archway. The Vitalit is hanging in the water under its arch.
3: Inside the well of the Crimson Shrine.
4: Near the Mover Shrine.
5: In the path that Pilot takes you through to the Prime 
Mover, veer left to a dead end. 

Master Of Forgotten Skills:
1: On the conveyor machine.
2: Inside a tunnel near the perimeter.
3: Inside a pipe of the conveyor machine.
4: Behind a column at the bottom of the pool.
5: Also inside the conveyor machine. 

Process That Never Ends:
1: Floating near the ceiling at the beginning of the conveyor tube.
2: In the fourth of five switch chambers to the left of the conveyor tube.
3: In the fifth chamber.
4: In a circular room at the end of the conveyor belt, hanging near the ceiling.
5: In the same room, tucked below under the glass and rocks. 

Blades In Motion:
1: Head through the floor from the starting point, then look up. The Vitalit is on the ceiling of this room.
2: In the wheel chamber before you get to the spinning blades. Follow the spinning room around to find it.
3: Once you are through the blades and break through the glass into the room surrounding the heated tunnels, you will find a Vitalit in the same room as the Endurance power-up and air supply. 
4: Once in the confusing tunnels, you will discover one Vitalit at a dead end. Go up at the end of the upper tunnels to find it. 
5: On your way down from the upper tunnels in a vertical tube. 

Perpetual Fluidity:
1: Near the floor by the pipes in the first shark room.
2: In the green switch room near the floor.
3: In the piranha room, near some pipes at the bottom of the pool. 
4: Once the water level is fully raised, head to the room past the piranha room (a dead end) to discover the Vitalit near the top of the tank.
5: Head all the way back through the piranha room, through the room with the Air power-up, across the hub room with multiple exits and to a dead end pool to find the Vitalit hanging near the top of the water. 

Obscure Ways To Terminus:
1-5: Each Vitalit hangs above the dividing rooms in the current chambers (labeled with stars). Leap over the barriers in the appropriate places to collect them. 

Sleeping Forces Of Doom:
1: Once you break the shield, a tunnel will open, giving you access to a single Vitalit. 

Anguish Of Dearth:
1: On the coral shelf near the top of the water.
2: On the floor of the starting pool, just below the first.
3: In a cove off of the main pool, directly across the pool from the starting point.
4: On the way to the tunnel that takes you to the big fish pool, you can get a Vitalit near the surface of the water.
5: Near the end of the tunnel, resting near the ocean floor. 

Entrapment:
1: Near the starting point.
2: Against the huge wall that bars entrance to the detention facility pool (to the left of the door).
3: Once you enter the detention pool, you will find a Vitalit above one of the spires of the detention facility.
4: Another Vitalit will be found on the opposite spire.
5: Search the wide tunnel off of the detention pool for the last Vitalit. It is near the end. 

Caverns Of Hope:
1: Above the surface of the water, you will find the first Vitalit at a dead end to the right after the first left turn. 
2: Near the rock floor in the second long hallway with explosive pods.
3: In the Globe pool, search the pods to the right.
4: Hidden in a pod near the Globe itself.
5: Near the end of the second leg of escorting your dolphin friend through the caverns. 

Lair Of Evil:
1: Head directly ahead from the starting point, ignoring the right path. In the middle of the circular pathway at the end of this tunnel is the first Vitalit.
2: Follow the right path from the starting point until you reach a hole that leads down. Swim inside to get the 
Vitalit.
3: After the laser tunnel, you will find a room with a bossy Clan Officer. Search this chamber for the third Vitalit.
4: In the largest room where their is a Clan Officer (the one that leads you to the control center), far behind him there is a huge image of the clan mark. The Vitalit is behind it.
5: In the large pool where you exit from. 

Powers Of Levitation:
1: Near the sand tube where the clan General leads you.
2: Outside the main generator building.
3: Inside the hidden room, where you go to play soccer.
4: Inside the central generator room.
5: Near the entrance to a fan tube (where you go to get the last few couplings). 

Hanging Waters:
1: Find the Vitalit in the first ball of water to your right, just as you start. It is in the bottom seaweed.
2: After you plunge into the rock pool, the next Vitalit can be found in the tube as you exit the other side.
3: Near the floor of the first pool (after Ice and Fire).
4: The pool below Abyss if Inferno.
5: In the pool immediately before the Mutaclone Boss. 

Ice And Fire:
1: Hanging above the air hole. 
Abyss Of Inferno
1: Search under the wall. 
Mutaclone
1: Inside the largest yellow rock. Break it open. 
Chance Of Reckoning
1: As you exit the long tunnel, to the right you will see a clump of seaweed. You will discover the first Vitalit here. 
2: To the right of the first whirlpool, atop some rocks.
3:Suspended above the surface of the pool over the third whirlpool (seal it before trying for the Vitalit).
4: Leap over the Queen's head.
5: Near the waterfall. Make sure you raise the water level (by clogging all three whirlpools) before trying for this one. 

The Hatchery:
1: Just past the left switch near the alien shark, you will see a Vitalit floating near the floor.
2: Get inside the air/food force shield to collect the second Vitalit.
3: Search the eggs near the machine arm. The left-most egg in the right row contains a Vitalit.
4: Follow the discarded eggs down the disposal.
5: Directly across from the starting point, near the ceiling. 

Seeds Of Poison:
1-3: Three Vitalits are in alcoves off of the main cave.
4-5: On the way up the egg chute, you will discover a pair of Vitalits. 

Transfiguration:
1: Above the surface of the air pool.
2: Near the ceiling of the chamber, near the central column.
3-5: Use your Power Of Sonar on the rocks near the Power of Morph to get the final three Vitalits. 

Heart Of The Foe:
1-5: Each Vitalit is hovering behind a membrane at the top of the heart chamber. Charge up to get each one. 

Gallery: Mystery area:
Go to the "Gallery" and head to the "Man's Nightmare" area (mechanical area). Look around the room to find two wheels. If you use your sonar on them, they will move. Quickly use your Sonar on both. If done correctly, the large metal circular object in the middle of the room will pop up slowly and reveal a secret passage. It leads under the Gallery to a room underneath the "Domain of the Enemy" area (alien area). The purpose of this new area is unknown, but may have something to do with the ugly thing hanging from the ceiling of the alien area.

Unlock All Levels: 
Do the following (you will need a memory card). 
Go to the [PLAYER MENU] screen and choose [NEW GAME]. 
Enter [GYU GYU ???] where ??? can be any three letters you want. 
Press the [CIRCLE] button on the controller. If the cheat has worked then a plant on the left side of the screen will release a huge stream of bubbles. 
Press the [X] button to create the save file, then return to the main menu. 
If you go to the [LEVEL SELECT] screen you will find that ALL of the levels have been unlocked. You may now select any level you want.