Metal Gear Solid 3 Extras
Warning: This section may contain spoilers.
Unlockable:
Stealth Camoflauge
There is more than one way to get stealth in this game
Complete the game without any alerts (don't worry if you get Caution. You just don't want Alerts).
Find and shoot all 64 Kerotan frogs throughout the game
Infinite Ammo
In the area where you fought The End, you need to find the Tsuchinoko (looks like an angry fat lizard with no legs) by first clearing out all the animals in the area. Once you have done that, you may notice one lone animal on your radar. Go find it and capture it with by using your tranquilizer or mouse traps. It needs to stay in your inventory until the end of the game. You might lose it again after you encounter The Sorrow. It will then be located by the water fall. If you keep in a cage until the end of the game, you will restart with the infinity face paint which gives you infinite ammo.
Mosin Nagant (Sniper Rifle with traquilizer rounds)
Defeat The End non-lethally (MK22)
Moss Camo (gives you 100% Camo Index on moss patches)
Carefully sneak up behind The End, then hold him up by holding down Square to aim.
Patriot (sawed off machine gun with infinite ammo)
Complete the game once to get the Boss's Patriot.
Tuxedo
Complete the game once.
Colt Single Action Army (Ocelots gun)
When the time comes, choose the gun on the right.
EZ Gun
There are two ways to get the EZ Gun which has infinite ammo
Start game on Very Easy
Capture all types of animals and plants in the game. Once they are captured, they are recorded as being captured so you don't need to worry about eating or rotting it. Just discard it if you want.
Cheats
Make The End show up on map:
At the map screen, enter UP UP DOWN LEFT RIGHT SQUARE TRIANGHLE.
Note that you will have to reenter the code when you leave the map screen. Alternativley, you can ran around until you hear him shooting at you.
Easter Eggs
Time Paradox: Ocelot
After you first meet Ocelot, you will have been through a cutscene. Then Ocelot and his troops will be on the ground unconscious (don't worry, they won't wake up while you are there). Toss a grenade on Ocelots body or shoot him. Once he is dead, you will get the Game Over screen with the voice of Colonel Campbell criticising you for changing the future. Without Ocelot, the other Metal Gear Solid titles could not take place the way they did.
Time Paradox: Eva
Any time you are with Eva, if you kill her you will get another Time Paradox. Without Eva, none of the Liquid, Solidus, and Solid Snake would not have been born, and therefore, the other Metal Gear Solid titles would never take place.
Metal Gear Models
In Granin's office, during a cutscene you may notice models of Metal Gear REX and RAY sitting on his desk.
Don't Save! (Para-medic's warning)
There will be a couple of times during the game where Para-medic will warn you that you may not want to save. They are during The End fight, and while locked up in the jail cell. The one with the jail scene was removed from the HD release since the game that was advertised in it has been scrapped.
For The End, you just want to leave the battle so that you don't see The End's health bar anymore. You will be safe here. If you save at the fight and wait about a week to play again, The End will pick you up because you fell asleep and throw you in an open jail cell back where you got the Key card.
In the prison cell that you are actually locked up in, if you save, leave an come back, you will get a mini dracula-like killing game. A dream Snake is apparently having due to his fear of draculas. This was removed from the HD release since the game was scrapped.
"I don't feel so good..."
If you or Eva ate something poisonous, then you can spin them around in Survival Viewer using the right analog stick. This will decrease stamina however.
"Snake!!!!"
When you are in the river with The Sorrow, call anyone. They will all think that you are dead (which you kind of are at this point).
Eva's Dreams
Shoot Eva with the tranquilizer gun to put her to sleep. If you listen carefully, she will say things about Snake. Hmm....
"He's so gullible"
When you come across the Glowing Mushrooms (your first encounter will probably be in the cave you fell in) call Para-medic to get information about it. Eat it, then call her again to get a funny conversation.
Bipedal Terd Tank
When you find yourself locked up in a prison cell, save the game. Para-medic will tell you it's a bad idea, but just do it anyway. When you restart the game, you will get the mini game of killing creatures. When you wake up, call Siginit to hear about his dream of the walking terd tank. You can also call your other friends to hear about their dreams.
Code to unlock cell door
Call 144.75 to unlock the door. Try to do this when the guard is in the bathroom however.
Secrets/Misc.
How to Interrogate a Guard (getting information)
It is possible to get some interesting information from the guards. If you carefully sneak up behind a guard and hold him up by aiming, he will put his hands up. Then hold O to put him in a hold. Alternatively, you can just immediately put them in a choke without doing a hold up. Keep in mind that the buttons are pressure sensitive, so don't hold it down too hard or you will slit his throat.
Once you have him in a hold, his life is in your hands. Hold the left analog down (L3) to put the knife to his throat as a threat, and Snake will say demand answers. Listen carefully, because sometimes they will even give interesting codec sequences.
Extra Waterfall Cutscene
If you leave in the transmitter from the prison, you will get an extra cutscene with Eva trying to take it out. However, the purpose of this transmitter is to track you, so becareful because the Ocelot unit will be waiting for you after encountering The Sorrow.
Hidden Johnny Cutscene
When in the prison cell, throw back the food 3 times. The guard will come up to you and talk to you about his family. His son named Johnny. Sound familiar?
Eat The Ends parrot
After you fight The End, if you use your thermal goggles, you may find The End's parrot in a tree or somewhere nearby. You can capture him and if you are that mean, you can eat it.
3 Snakes
When you are fighting The Boss, you can equip the Thermal Goggles, and on some trees, you'll notice maybe a larger snake hanging from some of the trees. There are 3 of them, one for each "Snake" that you and Eva will eventually name.
Extra pictures and info
With any person you can call in your codec, if you call them so many times, you will get a new picture with information. You can keep this up to get even more information, but it takes quite a bit of calls.
Kill The End early
If you have the SVD when you first watch the cutscene with The End (old guy in wheel chair) you have the oppurunity to snipe him. When the cutscene is over, you need to be sure it is equipped and look for him in the scope. You don't have much time, but if you hit him and kill him, his chair will explode and you will be hit. Alternatively, you will get a battle with the Ocelot Unit.
Snake's Nightmare
When you are in a jail cell, you should save your game. You will get a warning from Para-medic, but that's the point. After you save, restart the game and load your save. You will start off by being put into a mini game, killing zombies. Eventually you will wake up, either by dieing or just by time spent.
Defeat The End cheat
When you fight The End, save your game then turn off the PS2. Then set your clock for a couple of years later (not the week later like other sites have suggested or The End will catch you sleeping and send you to jail). If successful, you will see a cutscene after loading your save of Snake finding The End who died of old age.
Beat The Fear more easily
The Fears stealth feature kills his stamina so he will be looking for something to eat while fighting you. Well, his stamina system is like yours, which means if he eats poisouns/rotten foods, his stamina will decrease more quickly. This is done by collecting some of the poisonous or rotten foods before the fight, then throw them out once you encounter him.
Don't waste your food on Eva
This will also be helpful on focusing on clearing the area of guards. Tranquilize Eva and her stamina will slow down, but make sure she is somewhere safe like on a cliff or in a corner somewhere. This will also give you the oppurtunity to take out guards without worrying about Eva.
Good Vantage Point
When you are helping Eva escaped (after she has been injured), there is a good spot to put you and Eva while you have a good spot to shoot the remainind guards. This is in the second area after helping Eva climb the wall, and you will need to get by 2 more guards (if you are on Normal) to get to this area. Make sure to take them out, then head follow the wall on your left upon entering that area. You will find a little trail that leads to a cliff that gives you the view of the remaining guards. Note that they will be hard to spot, so either look carefully or use the thermal goggles.