“According to Hideo Kojima in the documentary Metal Gear Saga Vol. 1, the original plot of the game revolved around nuclear weapon inspections in Iraq and Iran and had Solid Snake trying to stop the Metal Gear while it was located on an aircraft carrier, in a certain time limit, while trying to stop Liquid Snake and his group. However about six months into the project the Middle East began to heat up again and they decided that they couldn’t make a game with such a plot. The tanker in the released game is based on this original beta plot.

Significant changes to the game’s ending were made late in development following the September 11 attacks in New York, where the finale occurs. A sequence depicting Arsenal Gear’s displacement of the Statue of Liberty and crashing through half of Manhattan was removed, as was a short coda to appear after the credits, a breaking newscast showing the Statue of Liberty’s new resting place, Ellis Island. At the point where Solidus dies, Raiden was supposed to have cut the rope on Federal Hall’s flagpole, causing an American flag to fall over Solidus’ body, and American flags which were supposed to be on all the flagpoles in New York were removed from the title.

Some pictures of Snake in an early prototype for MGS2, showed a Cell Shaded graphic. It originally was going to have a radically different art style, more on tune with the style of the concept art. This may have been from the proposed idea of the middle east storyline.” – wikipedia

Removed stuff: inondation into the tanker, the player must get away from the tanker, but Mr. kojima take off this idea because it was not funny to play. Chinaman, first design of Solidus snake and Vamp in woman version, were old concept art of character, later changed or removed. In another scene, Snake was attacked by the harrier in the city, on the big bridge, but this never happen in the final version (Raiden kills the harrier on the Plant). Probably this scene was cut because of the 9 / 11.

The model of the FAMAS not used in MGS2 was reused for MGS: The Twin Snakes for Nintendo Gamecube. Thanks to Grahamx227 for the contribution!

In 2006 Jesse Johnson & Marc Laidlaw from the MetalGearSolid.org community, shared and translated the original MGS2 Design Document that was written by Kojima / Konami as a guide to develope the final project. In this document (that you can download in here as a backup copy) there are a lot of interesting informations about removed scenes, unused gameplay elements and other stuff that was not revealed directly in the game. Here are some of the most interesting parts:

MGS2 was meant to be called Metal Gear Solid III: Instead of proceeding on to MGS2, as one might expect, we are making MGS3. The question in peoples’ minds, ‘Why is it 3 and not 2?’

In the previous game, only 4 to 5 enemies could be shown on-screen at a time. Now we will be able to display a maximum of around 300 enemies on-screen at a time.

We will create ways for the player to be able to control the brightness of their environment, making ‘light’ another strategy element that can be used in the game. All rooms have light switches that can be turned on and off. If you destroy a light, the area around it goes dark. If you equip the cigarette item while in the dark, it will emit a faint light

After an injured soldier has received treatment (lasting a set period of time) in a medical room, they will return to the game field. The area of the body where they were injured will be covered in a bandage texture. If you attack a medical facility, you can prevent this from happening again.

After Arsenal becomes active, the area with the hostages is cut loose. The bodies of the hostages (50 to 60) can be seen floating in the water, crimson from all the blood, and have attracted sharks. Raiden and Snake must proceed through the area.

A battle that takes place on Wall Street (at Federal Hall) – Snake versus Ocelot (controlled by Liquid’s right arm), and Raiden versus Solidus. Surrounding them are spectators and police officers, including mounted police.

It will be possible to deliver a type of attack with the hands while crouching or crawling whereby you grab an enemy’s legs and knock them over

In certain parts of the game, the game screen will be split up either horizontally or vertically, with one side of the screen showing a normal cut-scene. The other side will be the player’s game screen, so they will be able to continue playing while being able to see what is going on in the other screen. By doing this, we can display simultaneous sequences in real-time, showing what else is happening while a particular event is occurring. Split-screen scenes:  The bomb disposal scenes where Raiden, Snake and the bomb disposal consultant are all
working together.  Emma’s rescue (the sniping scene)

A type of hidden mode. By equipping an item called ‘Mantis’s Mask’, obtainable in the main game, you will be able to read peoples’ (enemies’) minds. [This was somehow used as an easter egg if you press the R1 or R2 button while Snake or Raiden is listening to someone,  you can hear their thoughts]

This will be a mode for split-screen two player battles in certain areas from the game. It will be compatible with system link-up as well. Players can either fight each other or play a hide-and-seek type game.

In addition, the player will be able to virtually explore the ocean floor through a remote-controlled minisub, and can also save pictures taken with its camera.

Member of Dead Cell. A soldier over 100 years old. A legendary hero from the Second World War, he taught Big Boss and the world’s mercenaries everything they know about combat. As a Nazi, he was feared as the ‘Old Boy’, or the ‘devil’. He fights with weapons and equipment used during the war, such as the Panzerfaust.

Removed Bosses: The President’s security team, the Great white sharks [probably used in the scene where the bodies of the hostages  floating in the water would had attract sharks]

The May 10th 2012, RushSnake and WhiteSnoop (two of the founders of Red Code Interactive‘s team) has found some interrestings stuff on Metal Gear Solid 2. A weapon named SPP1M on the trial version of Metal Gear Solid 2 has been discovered, along a lot of strange items and others weapons.

Thanks to Solidshake for some of these infos and images! Thanks to Jonathan and A.Kyanbel for the contribution!

Images:

Videos:

You can see a demostration of all items and weapons found in this video