Medal of Honor: Rising Sun Hints

When doing the 4th mission, Midnight attack on Guadacanal, when the second soldier leaves you and and the other character to ''cover you'' from behind, go in front of him and push him through the level by walking into him. You will have to angle some pushes too. After pushing him a bit, he will vanish and never be seen again, even if you go back to the spot he was originally at.

The trench tool digs up dirt for in game secrets. To find the tool you must get to the level named Search of yamashitakas gold and find the lotus flower on a statue inside the palace. Walk up to the front of it and you'll pick it up. After you fall down the hole, go down to the end of the hall into a room with a gold statue. There is a pedsetal. Press X on it and it should say, "YOU HAVE REACHED ENLIGHTENMENT." Then a door will appear to the right and in there is a hammer-like tool.

(You need the entrenching tool in order for this to work.)
On the Supercarrier Sabotage level keep opening doors until you find a locker room with soldiers in it. Kill them and walk toward the dark locker. Press X on the locker and you should have unlocked the bonus option ''Immortality''.