Duke Nukem 64

GT Interactive
Genre: 3D Shooter
Players: 1-4

All Items
Enter the CHEAT MENU code shown below, then return to the main menu and press R, C-Right, Right, L, C-Left, Left, C-Right, Right. A new item called "ALL ITEMS" should become available.

Big Duke, Little Duke
There is a way to play big or small in Duke Nukem. This code will work on co-op or deathmatch. To do this code in co-op you need Invincibility and items codes. Turn on friendly fire, then use the weapons code, shoot your buddy with the shrinker, or expander.

Small Duke: Shoot, put on invincibility then turn it off again. The player will not grow back (the drawback: you can't have any weapons).

Big Duke: Get the expander, (with God mode off) and shoot the other Duke until he starts to expand. Just before he explodes put on God mode, stop shooting, then turn off god mode. You now have a giant duke that still can be killed. (Note, you may have to try it a few times to get it right.)

Cheat Menu
At the main menu press Left, Left, L, L, Right, Right, Left, Left to access the Cheat Menu.

Come Fire Walk With Me
You can safely walk on lava for a infinite amount of time by pressing the jump button enough that your feet aren't on the ground for more than a second. Keep it up and you can stay in lava without protection for as long as you want.

Fountain of Youth
It's always fun to blow stuff up right? Well now you can have fun and get power at the same time. First, the fun part: shoot or blow up a water fountain, fire hydrant, or even a toilet. Then walk over to the water that's squirting up and hold "A" {default}. You will gradually regain your energy.

How do you Spell Relief?
If you're low on health, take Duke to a restroom and stand him in front of a toilet or urinal. Press the action button (A by default) and Duke will relieve himself for some health.

Infinite Jet Pack
While you're in the air with the jet pack, turn on the All Items code. You now have unlimited fuel for your jet pack.

Invincibility
Enter the CHEAT MENU code shown above, then press R seven times followed by LEFT on the d-pad (not the analog stick.) If you did it right you'll hear a tone. Now go into the cheat menu and turn invincibility on.

Level Select
Enter the CHEAT MENU code shown above, then press L, L, L, C-Right, Right, Left, Left, C-Left.

No Monsters
Go to the cheat menu (see above) then press L, LEFT C, LEFT, R, RIGHT C, RIGHT, LEFT, LEFT, RIGHT. You will hear a siren if you did the code correctly. Then go in the cheat menu and now you can turn the monsters on and off.

Weapon Warp
In Deathmatch, any weapon can be throwm into a teleporter to have it appear on the other end. Bullets, missles, grenades, plasma, it all goes through. You have to wait for the item to completely pass before you can throw in another, ie., rapid fire bullets will not go through. This is great for dropping gifts on your opponents while you stay safe. Just be careful not to stand on a teleporter for too long, because if someone else steps on it, you'll get telefraged.