Press P to pause the game, type the code (case-sensitive) and press Enter.
Easy Mode must be entered first to enable the other codes.
fortytwo - Easy Mode (enables other codes and cheat keys)
dwarf - Small character
baffe - Big hands
bigfoot - Big feet
bighead - Big head
normal - Normal character
muchbetter - Arkhan relieves himself
Cheat keys:
Ctrl-D - Refill Arkhan's life gauge
D - Decrease opponent's life to 1