LOWER JUNGLE MAZE - West, West, Northwest, and West.
UPPER JUNGLE MAZE - Southwest, Southwest, North, Southwest.
The music will change if done correctly
In the areas where small holes open up and swallow you up, quickly press pause and unpause. They freeze so you can go around them.
At the end of the game, you can equip the cigarettes to reset the timer when it runs out. Helpful if you're fighting Big Boss.
You can cause items to reappear by pressing SELECT and going into a menu, and returning back. You can do this as long as you want. You can also do this by walking in and out of the room, but it takes too long.
Here are some passcodes. Enter them by selecting "CONTINUE" on the title screen.
21Z1C GZZZG UOOOU UYRZZ NTOZ3 - Start with all items and weapons.
3LLLL LLLLL LLLLL LLLLL LLLLL - Skip to the cell with items you normally do not have at this point of the game.
DIANE ELLEN JENNY FERBY GBOSS - Bypass to Big Boss battle.
TOOOU TOOOU TOOOU TOOOU TOOOU - Bypass to the end of the game. Choose the left elevator.
If you want to skip directly to Big Boss rather than blow up the Super Computer at the end of the game, hold "RIGHT" while entering the room where the Super Computer is being held at.
If done correctly, you will see the Super Computer room flash and then you'll be in the room Big Boss fights you with no timer!