Full items
Collect the items from a room. Exit the room and return to re-collect the items.
Full health and jetpack power
Press B + I + G.
Display coordinates
Press [Ctrl] + [Alt] + [Right Shift] + [F12].
Soundtrack
Insert the game disc into an audio CD player. Play tracks two and above to hear music from the game.
Hidden tunnel
In the temple of Bu on White leaf Island, go under the first lift (near the two guards). There should be a tunnel that leads to the section with the knives and statues that shoot fireballs.