Indiana Jones and the Emperor's Tomb Cheats

Indiana Jones and the Emperor's Tomb Cheat: Hold 3 Grenades At a Time
You can only hold two grenades at a time. If you need to hold one more, do this: make sure you have two grenades in your satchel. Grab a third one; it will not let you put it in. Instead, he will drop it. Hold it in your hand and jump into water deep enough for you to swim. When you get out of the water, check your inventory. Under grenades, it will say 3/2.

Indiana Jones and the Emperor's Tomb Unlockable: Art Gallery
To unlock the Art Gallery, find all of the artifacts in the game.

Indiana Jones and the Emperor's Tomb Hint: Avoid Damage From Falling
To avoid damage from falling, enter Combat Mode just before you hit the deck, and you won't incur any harm.