To use the following codes type them in the game while playing:

SHERLOCK - Gives all puzzle pieces
VISITx - X = Number of the level you want to teleport too
LOCKSMITH - Gives all keys
CASPER - Toggles clipping on and off (move through walls)
MAPSCO - Shows whole map
MAPSCOMAPSCO - Shows the whole map and all items
NRA - Gives all weapons
KILLS - Displays a kill counter if you are playing DM
BUTCHER - Kills all enemies
DELIVERANCE - Transforms you into a pig
CLUBMED - Gives full health
INDIANA - Full ammo and items
SATAN - Invulnerability
TICKER - Display your frames per second