The Mummy Returns

Unlimited ammo:

Hold up on the directional pad (NOT the analog stick), then press circle, square, triangle. A screen should appear. On that screen hold square a few seconds later AMMO should come up on the screen. When that appears press x.

Invincibility:

As Rick gets to Ahm Shere and go to the middle of the place. Then press start to pause the game and press up,down,left,R1,R3,Triangle. The pause screen will go and you should go back to the level and your life bar should go up to full if it already is not and it should stay there throughout the whole game.