Various Cheats
     During  gameplay,  press F1 or ~ for console. Now type any of the
following "Codes" in the console:

Code                    Effect 
please god              God Mode 
please giveall          All Items 
please killall          Kill All Enemies 
please open             Open All Doors 
please fly              Flight Mode 
please ghost            No Clipping Mode 
please invisible        Invisibility 
please tellall          ??? 
please refresh          ???