While playing the game, press [Enter] and type "-" followed by "gui". The character pictures, compass, buttons, and everything except for what is actually going on in the game will disappear. You also will not be able to see what you are typing when you press [Enter]. Use the "+gui" code to return to normal.
Cheat Codes
While playing the game, press [Enter] and type one of the following codes to activate the corresponding cheat function. To disable a code, type "-" followed by the code.