Bug: If you fall in the water, your hat is temporarily removed, and when you go back to the surface, you have it on again. Well, if you get out of the water, and make Indy fall to the water just in the moment when he's putting his hat back on, it'll fall in the water and you can play the level with no hat.
Bug: During the first Netherworld levels, small chunks of the Terra-cotta soldiers still remain wobbling in the air after being defeated.