Misc. Unlockables:
Gun Shooting Mode Enter the VR training mode and successfully complete training mode time attack mode(look for cheat on list). When your done re-enter VR training mode, you'll find the new option.

Infinite Ammo Do not submit to Ocelot's toture and at the end you will get Meryl's ending. She will give you a bandanna. Load the game and you will have the bandanna. Equip it and you will have infinite ammo.

Tuxedo Beat the game twice, one with Meryl's ending, once with Otacon's ending. Save them on the same slot. Load the new game and when Snake goes up the elevator in the Dock, Snake will change into a tux.

Stealth Beat the game and submit to Ocelot's torture. Otocan will give you his stealth camoflauge. Load the game and you will have stealth. Equip it and you will be invisible, although wolves can see you and when an FMV shows the guards will see you.

Time Attack Enter the VR training mode and succesfully complete training mode. When you re-enter VR Training Mode, you'll find the new option.

Technical Demonstration Mode Complete all other VR Training modes

Extreme Mode Complete the game on any mode and start a new one.

Survival Mode Complete Gun Shooting Mode in VR Training

Demo Theater Mode Complete the game with either ending; complete both endings to completely unlock this option.

Hear the MGS theme tune play during the end credits Beat the game 3 times on the same save file. The official Metal Gear Solid themetune will play during the second half of the end credits

Fight Red Ninja Beat the game with 100 percent two times, then go fight the ninja.

Camera Complete the game and submit to Ocelot's torture, then start a new game.

Different ending/music:
Different ending/music Beat game while wearing the Tuxedo

Special Message:
If you have a savegame of POLICENAUTS on your memory card when you fight Mantis, you will get a special message from Hideo Kojima.

Get Mei Ling Mad:
Keep calling Mei Ling on the codec. Say do not save about 5 to 8 times. She will get mad eventually and stop talking to you.

Castlevania Message:
If you have a save game of Castlevania: Symphony of the Night on your memory card, Psycho Mantis will give you surprising message before you fight him.

Suikoden Message:
If you have a Suikoden Save Game on your Memory Card , Psycho Mantis will give you special message regarding Suikoden when he reads your mind.

Save message from Psycho Mantis:
If you save enough times before fighting Psycho Mantis he will tell you how wise you are for saving often.

Alternate Save Message from Psycho Mantis:
If you save less than three times before you fight Psycho Mantis, you will get a special message on how reckless you are.

How to make the Ninja free you:
After you are tortured, thrown in the cell, and called Otacon, the guard goes to the bathroom. Otacon comes, gives you a few things and then when he leaves and the guard comes back, let the guard go to the bathroom 2 more times. When the guard goes to the bathroom the second time, you'll hear something like a FAMAS. The Ninja comes and frees you!

Ghost Picture of Hideo Kojima:
After you beat the Ninja, take your camera and take a picture of the picture of the big orange-like robots in Otacon's lab. When you've done it, reset and load the picture. You'll see a ghost picture of Hideo Kojima!

Title Screen Tricks:
When you reach the title screen, push any of the directions on the D-Pad to be able to get different colors for the background graphics.

Defeat Psycho Mantis with ease:
Make the boss fight with Psycho Mantis much easier by switching your controller to port 2 when the message HIDEO appears on your screen. If you do it correctly, Psycho Mantis will be unable to read your thoughts making the fight much easier.

A more useful cardboard box:
When you're in the cave area with Meryl, hit her and quickly equip a cardboard box. She'll order a wolf to attack you, but if you're in a box, a wolf will pee on it instead. Now whenever that box is equipped the wolves will no longer attack you.

Easily cross minefields:
If you don't have the mine detector, but want to cross a minefield without having to worry about blowing up, just go up to the area where you believe mines are and crawl across the ground. Not only will you be unharmed, but you will also receive any claymore mines that you crawl over!

Otacon's Ending:
To view Otacon's Ending instead of Meryl's ending after completing the game, submit to Ocelot's torture after being captured.

Meryl's Ending:
Resist Ocelet's torture to see a happy ending where everyone lives. You can use a turbo controller.