Full health, ammunition; all weapons, keys
Press L + I + M during game play. Note: Your score will reset to zero after this cheat is enabled.
Commander Keen cheat message
Press A + B + T during game play.
Press [Tab] + G + [F10] during game play.
Hold M at the memory screen that appears while the game loads. A music menu option will appear after the game finishes loading.
first cheat:Easter Egg !!! (on some versions) :
Change screen size
Hold I + D + [Esc].
Start the game with the "-tedlevel"<mission number> command line parameter.
Skip the Question(s) at the Beginning of the Game
If you don't have the booklet that has the information required to answer the questions when you first load up the game, you don't have to look up the answers online. Instead, all you have to do is type "joshua" as your answer. No matter what the question is, if you type joshua, it gives you a nice little message and let's you right into the game.
Start the game with the "-debugmode" command line parameter. Press [Left Shift] + [Alt] + [Backspace] to enable debug mode. Enter one of the following codes to enable the corresponding cheat function.
|Change border color||[Tab] + B|
|Display number of items, doors, and actors||[Tab] + C|
|Level skip||[Tab] + E|
|Displays coordinates||[Tab] + F|
|Toggle God mode||[Tab] + G|
|Lose health||[Tab] + H|
|Free items||[Tab] + I|
|Display memory usage||[Tab] + M|
|Walk through walls.||[Tab] + N|
|Pause without message||[Tab] + P|
|Exit game||[Tab] + Q|
|Toggle slow motion||[Tab] + S|
|View graphics and play sounds||[Tab] + T|
|Add extra VBLs||[Tab] + V|
|Level select||[Tab] + W|
|Extra stuff||[Tab] + X|