Indiana Jones and the Emperor's Tomb

Indiana Jones and the Emperor's Tomb cheat codes: 
Find the default.cfg file. Go to GameData/indy/default.cfg
and edit it using notepad. (Be sure to back it up first)

Change the file to read as follows:

pack:0
title:0
freescenedata:1
vsyncinterval:2
milessound:1
nocontrol:1
cheats:1
resmgrload:res.dat
fullscreen:1

Save the file and run the game.

You will now have access to the builtin cheat mode with the following cheats:

Unlimited Health
Unlimited Oxigen
God Mode
Unlimited Ammo

Disable AI:
Note: This procedure involves editing a game file; create a backup
copy of the file before proceeding. Use a text editor to edit the
"vars.cfg" file in the "\lucasarts\indiana jones and the emperor's
tomb" folder. Locate the "aiDisabled" line and change it
to "aiDisabled=false".

Art gallery:
Collect all artifacts in the game to unlock an art gallery.