To activate cheat mode, start the game with the command "PRINCE MEGAHIT". (Type "PRINCE IMPROVED" if you have version 1.3). The following codes are now available during the game.

Code       Effect
Shift-L    Skip to next level
Shift-T    Extra bar of energy
Shift-W    Feather fall
Shift-I    Flip Screen
Shift-B    View Animation/Sprites
Shift-S    Drink Small Potion
C          View code
V          View screen to the top
H          View screen to the left 
J          View screen to the right
N          View screen to the bottom
K          Kill all on-screen enemies
+          Increase Time
-          Decrease Time