Metal Gear (NES)/Changes from the original

There are two different versions of this game. The original was developed for the MSX2 home computer by Hideo Kojima, and the NES version was programmed by a separate team at Konami. Other versions, such as the Commodore 64 and MS-DOS versions of the game, are based entirely upon the NES conversion. Of the two versions of the game, the NES version is far more common and popular among North American players. However, this version contains a number of changes to the game that were made without consultation from Kojima, who has stated his dissatisfaction with a number of details of the conversion. In addition to having different soundtracks from one another, and a slightly better look on the MSX2 due to a higher resolution and palette count, many aspects of the game were changed.

Presentation

MSX2	NES
The attract mode shows a conversation between Snake and Big Boss that explains several of the controls used throughout the game.	The attract mode shows brief examples of gameplay.
In the English version of this game, published throughout Europe, a few cases of the transceiver communications were cut from the dialog, reducing the story element of the game somewhat.	The English version of the game contains numerous misspellings, and examples of "Engrish." Some terms like "wind" and "wall" have been mistranslated into "window" and "way."
Snake shows up outside building 1 alone by swimming up to the entrance. After talking with Big Boss, he can walk right up to the door and enter the building.	Snake supposedly sky dives down from a plane with a parachute along with three other soldiers. He lands in a jungle far from building 1 and must traverse south through the jungle and hop in a truck that will transport him to the entrance.
Some trucks contain guards. If you wait outside of certain trucks long enough, a guard may step outside of the truck, do a quick patrol around it, and return back inside.	Some trucks contain guards, but no matter how long you wait outside of them, they will never leave the trucks.
The inventory list is sorted in the order of oldest item to most recently obtained item.	The inventory list is presented in a presorted manner, with an assigned location for every item.
A animated picture of Solid Snake is present on the Transceiver screen.	No picture of Solid Snake is shown on the Transceiver screen.
When you gather your items after being captured, the item in your equipment which reveals your location is called a "Bug" and looks like a small device.	When you gather your items after being captured, the item in your equipment which reveals your location is called a "Transmitter" and looks like a sizeable radio.
The infra-red goggles causes much of the screen to turn gray, making the red laser beams stand out more.	The infra-red goggles do not change the color of the screen, they only make the lasers appear red.
Pitfalls appear more three dimensional as they are drawn with some depth. They do not appear until later in the game.	Pitfalls are merely black squares, and can appear as early as the first floor of the first building.
Towards the end of the game, Snake does encounter a Metal Gear. It is stationary, but it is defending by two wall-mounted laser defense systems. Snake must follow Dr. Pettrovich's precise instructions in order to destroy it, although the doctor fails to recall the very last step and you must correctly guess it on your own.	Throughout the game, Metal Gear is never seen. Towards the end of the game, Snake must instead destroy a super computer that is said to control all of Metal Gear's functions. There is no special sequence to remember in order to destroy the computer.

Enemies

MSX2	NES
When you knock out an unsuspecting soldier without weapons, only punches, there is a chance that they will drop rations or ammo.	Soldiers never drop items when you knock them out.
When guards are alerted to your presence, they will go into one of two alert modes. One is a low alert that only affects the guards in the room, does not summon backup, and is easy to escape from. The other is a high alert (also triggered by security systems) that causes backup to arrive, and cannot be ended simply by changing rooms.	When guards are alerted to your presence, they only go into one kind of alert mode. In this alert mode, backup security is always summoned like the original's high alert mode, but the alert can be ended simply by changing rooms like the original's low alert mode.
Dogs can't be punched, they can only be shot.	Dogs can be punched as well as shot.
Cameras have no blind spot. The only way to avoid direct detection is to remain motionless inside of a box when they pass you.	Cameras have a blind spot immediately in front of them. If you hug the wall that they are mounted on, you can safely escape detection.
Soldiers that wear jet packs can lift off the ground and attack you while they fly around in the air.	Soldiers that wear jet packs can not lift off, and attack from the ground in the same manner as all other soldiers.
Soldiers can see through the grating on the first floor of the second building.	Soldiers can not see through the grating on the first floor of the second building.
Scorpions are better at detecting and tracking your position across the desert.	Scorpions are a little slower to react and chase you as you cross the desert.

Gameplay

MSX2	NES
There are a few trucks which transport you around the game, primarily back to the courtyard in the first building.	There are many more trucks that transport you around the game, some leading to advanced areas that you may not be equipped to explore yet.
It is usually possible to avoid being detected no matter how you enter or exit a room from.	There are some points in the game where it is impossible to avoid detection no matter what you do.
Continuing after death causes you to reappear at the most recent particular check point you've passed, like entering an elevator, or exiting a building.	Continuing after death causes you to reappear at a predetermined location, based solely upon your current class rank.
Bullets from guns only travel a certain distance from Snake before disappearing.	Bullets from guns travel completely across the screen, enabling Snake to hit targets that are farther away.
Before you can collect the Silencer, you must fight four armed soldiers who shoot at you from behind crates.	The Silencer is undefended, and can be collected immediately.
When you are captured, you are taken to the basement of the first building (the same building in which you were captured.)	When you are captured, you are taken to an entirely different building.
In order to break holes in the wall, you must either punch a wall several times in succession, or plant an plastic explosive, when you find a weak point (hear a different sound when punching the wall.)	Weak points in wall automatically break open with one punch when you find them.
When you approach the right door in the fight with Shoot Gunner, you must punch it in order to make it open.	When you approach the right door in the fight with Shot Gunner (renamed), the door will open automatically.
On the roof of the first building, the bridges are longer, the boss is a stationary Hind D that shoots at you, and you must jump off the roof with a parachute to reach the courtyard below.	On the roof of the first building, the bridges aren't as long, the boss is the Twin Gunners, and there is no parachute or jump off point.
On the approach to the tank, several screens of ground are lined with mines, and the tank shoots mortars at you while you attempt to get close to it.	On the approach to the tank, only a few mines are on the ground above a truck. The tank is found just one screen above it. It does not shoot mortars as you try to reach it.
Visiting a sub-screen does not reset the position of any enemies or cause pitfalls to stop expanding, although it might restore a previously collected item like ammo or rations.	Visiting a sub-screen does reset the position of bosses and it does stop pitfalls from expanding (when you return, the floor is covered but the pit still exists), as well as restore previously collected items like ammo or rations.
A fake Dr. Pettrovich is found in the basement of the second building, and the real Dr. Pettrovich is held on the second floor of the second building. The fake doctor falls through the pitfall after it opens.	A fake Dr. Pettrovich is found in the second floor of the second building. The real Dr. Pettrovich is in the fifth building (which has the same floor plan as the original second building basement.) The fake doctor remains suspended in mid-air after the pitfall opens.
To escape the building before the self destruct sequence counts down, Snake must choose one of three ladders to climb. The wrong ones end prematurely.	To escape the building before the self destruct sequence counts down, Snake must choose one of three elevators to enter. The wrong ones rise indefinitely.

Maps

MSX2	NES
There are three buildings.	There are five buildings, although the two new buildings have the same floor plan as the basements which were removed from the first two buildings.
The first building has five floors, including a basement and a rooftop. The first floor has a courtyard that you must parachute into. You find access card 4 there.	The first building only has four floors, including a rooftop but no basement. The first floor does not contain a courtyard. The basement of the first building has become an entirely separate building. Access card 4 is found outside of the building.
The basement of the first building contains a maze made out of corridors that are filled with poison gas. Snake must find weak points in the wall and blast holes in them with plastic explosives to reach many key items.	The fourth building, which is based on the original first building's basement, is drastically simplified, with the maze and the poison gas removed entirely.
The second building has four floors, including a basement and a rooftop. The basement of the second building is connected to the basement of the first building by way of a darkened tunnel with pitfalls.	The second building only has three floors, including a rooftop. The basement of the second building has become yet another separate building, but these two new building are still connected by the darkened tunnel with pitfalls.
The only outdoor portions exist between the first and second building, and between the second and third building.	The outdoor portions of the game have been significantly expanded, including the entirely new jungle sequence at the beginning of the game, and the two original outdoor sections each include a forest maze screen that leads to the entrances of the new buildings.
A few openings in the final building must be discovered and blown open in order to access what lies behind them.	Many openings are immediately accessible with no action required on your part.