Select the ''New Game'' at the VMU menu, then enter GYU as a name but do not select "End". Enter GYU as a name for that game again, but do not select "END". Then, enter any letter three times as a name and press X. If done correctly, you will be returned to the VMU menu. You can now create a new game as usual or resume a saved game. The next time you save the game, all levels will be unlocked. Additionally, a choice for the soccer mini-game will appear at the bottom of the level selection screen.

Hold X (sonar) during game play for a long time. Press X again to return to normal.

Press Start to pause game play, then press X + Y.

Encounter the Boss in the "Blades..." level. It is a large room with a Boss that resembles a large dragonfly larvae. Go to the bottom of the room where you can refill you air supply with the bubbles coming out of the ground. Next to the bubbles on the floor near the wall is a small hole. Go through it and get outside the game world.