Type "1982gonzo" or "gonzoopera" while Duke is selected during game play to enable cheat mode. Then, activate the following cheats by entering the corresponding codes:. Note: If gonzoopera does not enable cheat mode in your version of the game, create a backup copy of the "commando.cfg" file in the game directory. Then, use a text editor to add the line ".DEVELOP 1" in that file:

CHEAT FUNCTION - CHEAT CODE
Place selected commandos under the pointer - SHIFT + X
Mission skip - CTRL + SHIFT + N
Trace user - SHIFT + V
Invisibility - CTRL + I
Destroy everything - CTRL + SHIFT + X
Mission editor - SHIFT + E or CTRL + E
Select video mode - SHIFT + F1 through F4
View debug output - CTRL + F9
Invincibility - CTRL + L
Display terrain information - F9
Window help - ALT + F11
Picture interface - ALT + I
Write data to "memlin.dat" - ALT + SHIFT + L
Write data to "memact.dat" - ALT + SHIFT + M

Access the following levels by entering the corresponding passwords:

LEVEL - PASSWORD
The Asphalt Jungle - 8K2IX
Dropped Out Of The Sky - 9R29I
Thor's Hammer - 4469J
Guess Who's Coming Tonight - 4HSAB
Eagle's Nest - J8TSN
The Great Escape - LUK2L
Dangerous Friendships - DUSL2

-To easily complete certain missions, massacre all the Nazis. To do this, go to a semi-hidden place where the Nazis must to make a right or left turn before they can see you. You must be in range to shoot them with a pistol before they can see you. For example, in the "The Asphalt Jungle" mission, a recommended place to do this is behind the wooden fence near where the zoo keeper turns to go back inside the zoo. When you are in place, fire a warning shot. Nearby Nazis will hear it and run towards your location. They will fall in line while running to you. Start gunning them down when they come into sight. You will see them first and kill them before they see you (three shots per soldier). Note: This cannot be done in missions that require stealth.

-When trying to kill a tough soldier, stand up momentarily. When he is looking at you with the light green line of sight, go back down and hide. The Nazi soldier will approach to investigate without raising the alarm. You can now kill him easily.

-It is tough to win without killing the three Nazis who are ready to shoot the captured general. To kill them, get the zookeepers uniform for the Spy and go inside and move to the area where the captured general is held. Stand just behind one of the three enemy soldiers. Click the soldier to push him one step forward, then move him until he is one or two steps next to the captured general. Do the same thing with the second soldier. Then, use ether and injections to kill the third soldier. Hide his body. Push one of the other soldiers to back and kill him. Then, kill the third soldier. Finally, hide the general behind some barriers (just in the back side of that wall). You can now kill enemy soldiers and no longer need to hide them.

-Kill the soldier outside the compound wall (near the lion's cage) to trap three more soldiers there.

-Make use of the yard house across the street to hide bodies.

-The cigarettes are useful for drawing enemy soldiers into the bear trap.