Duke Nukem: Zero Hour Codes -

First person view:
Press Down, Up, L, B, Z, Left, C-Up, C-Right, C-Left, Z when "Press Start" appears at the opening screen. A sound will confirm correct code entry.

Shotgun and unlimited ammunition:
Press Up, Down, Left, Right, L, R when "Press Start" appears at the opening screen. A sound will confirm correct code entry.

Freeze Thrower and unlimited ammunition:
Press Down, Up, A, L, R, Z when "Press Start" appears at the opening screen. A sound will confirm correct code entry.

Rifle and unlimited ammunition:
Press C-Up, C-Down, C-Left, C-Right, L, R when "Press Start" appears at the opening screen. A sound will confirm correct code entry.

Multi-player character set 1:
Press A, L, R, Left, B, Down, Up when "Press Start" appears at the opening screen. A sound will confirm correct code entry.

Multi-player character set 2:
Press B, A(2), R, L when "Press Start" appears at the opening screen. A sound will confirm correct code entry.

Multi-player character set 3:
Press L(2), Up, Down, R, B, A when "Press Start" appears at the opening screen. A sound will confirm correct code entry.

Multi-player character set 4:
Press B(3), R, Left, A when "Press Start" appears at the opening screen. A sound will confirm correct code entry.

Multi-player character set 5:
Press Right, B, Left, L, A, Z when "Press Start" appears at the opening screen. A sound will confirm correct code entry.

Multi-player characters set 6:
Press Up, Down, B, A(2), Left when "Press Start" appears at the opening screen. A sound will confirm correct code entry.

Skin select:
Press C-Left, R, Left, Up, Down, B, A, Z when "Press Start" appears at the opening screen. A sound will confirm correct code entry. Skins may be selected in single player mode, but may not be viewed during selection.

Action Nuk'em mode:
Press Down(2), A, Z(2), Left, A when "Press Start" appears at the opening screen. A sound will confirm correct code entry. Alternately, successfully complete the game. This mode allows Duke to kill opponents with one shot.

Extreme mode:
Successfully complete the game with all babes rescued and all opponents killed to unlock Extreme mode, which allows the game to be played at a higher difficulty setting.

Big head mode:
Rescue all babes in level 2, "Liberty Or Death", to unlock the cheat option for big head mode.

Big gun mode:
Kill all opponents in level 3, "Nuclear Winter", to unlock the cheat option for big gun mode.

Flat shade map:
Obtain all secrets in the secret "Wetworld", level to unlock the cheat option for flat shade map.

Ice skin:
Rescue all babes in level 5, "Fallout", to unlock the cheat option for ice skin.

Weather:
Obtain all secrets in level 6, "Under Siege", to unlock the cheat option for weather.

High speed zombies:
Rescue all babes in level 8, "Dry Town", to unlock the cheat option for high speed zombies.

Maximum blaster ammunition:
Kill all opponents in level 9, "Jailbreak", to unlock the cheat option for maximum blaster ammunition.

Maximum shotgun ammunition:
Rescue all babes in level 10, "Up Ship Creek", to unlock the cheat option for maximum shotgun ammunition.

Maximum rifle ammunition:
Rescue all babes in level 11, "Ft. Roswell", to unlock the cheat option for maximum rifle ammunition.

Maximum revolver ammunition:
Rescue all babes/obtain all secrets in level 12, "Probing The Depths", to unlock the cheat option for maximum revolver ammunition.

Maximum sawn-off shotgun ammunition:
Kill all opponents in level 13, "Whitechapel Killings", to unlock the cheat option for maximum sawn-off shotgun ammunition.

Maximum SMG ammunition:
Obtain all secrets in level 15, "Dawn Of The Duke", to unlock the cheat option for maximum SMG ammunition.

Maximum gatling gun ammunition:
Kill all opponents in level 16, "Hydrogen Bomb", to unlock the cheat option for maximum gatling gun ammunition.

Maximum Volt C. ammunition:
Obtain all secrets in level 17, "The Rack", to unlock the cheat option for maximum Volt C. ammunition.

Maximum sniper ammunition:
Rescue all babes in the "Going Down" secret level to unlock the cheat option for maximum sniper ammunition.

Maximum freezer ammunition:
Kill all opponents in level 20, "The Brothers Nukem", to unlock the cheat option for maximum freezer ammunition.

Maximum gamma ammunition:
Rescue all babes in level 21, "Alien Mothership", to unlock the cheat option for maximum gamma ammunition.

More multi-player characters:
Complete any level and save the game to unlock one additional character in multi-player mode.

Hint: Health refill:
Destroy a fire hydrant, toiler, water pump, or another water source. Run up, stand in the water and repeatedly press B to slowly restore Duke's health until it reaches 100. Also, if you see a concentrated area of purple objects appearing from the ground, stand on it to refill your health.

Hint: Wetworld level:
Play through the "Nuclear Winter" level until reaching the rail tracks leading to the communicator. Power up and drop off onto the roof below where a medi-kit can be seen. Jump off this roof into the water (which is only on one side). Swim to a floating platform, where the level exit will appear.

Hint: Going Down level:
Locate all the time machine pieces before reaching "The Rack" level and a second exit portal should appear in the room just off where the first is located. Use it to reach the "Going Down" (Titanic) level.

Hint: Easy Western period Boss kill:
Get the sniper rifle before facing the giant scorpion at last stage of the western time period. Go out to the entrance when you can barely or see half of the scorpion. Pull out the sniper rifle, aim at its body, and start firing.