The MSX version of this game, together with Metal Gear 2: Solid Snake is featured on the extra disc of the Limited Edition of Metal Gear Solid 3: Subsistence.
The NES version of Metal Gear is listed in the 2008 Guinness World Records Gamer's Edition as the first game to fully utilize stealth as part of the gameplay.
Michael Biehn from "The Terminator" film, though not authorized, was used as the model for the box illustration. You can find a side by side comparison here: http://www.flickr.com/photos/echo5ive/133374501/
The original version of Metal Gear was released for a personal computer known as the MSX in Japan and Europe. The better-known Famicom (NES) version was released in Japan half a year later after the MSX version was released. Hideo Kojima, the game designer who worked on the MSX version, was not directly involved in the NES port and the game's was handled by a different Konami team at Tokyo. As a result, the developers made a few compromises from the original MSX game.
A different intro was added where Snake parachutes into a jungle (instead of the underwater insertion of the original), the areas were rearranged (and a new maze was added) and two of the bosses (the Hind D and the Metal Gear itself) were replaced by different.
The NES version was also poorly reprogrammed and various subtle gameplay aspects were modified. The player's gunshot's range were extended, the jetpack soldiers on the rooftop lost their ability to fly, you cannot leave a door open and switch to the item/weapons screen, the Lv. 3 or "double exclamation mark" Alert mode (where the alarm isn't deactivated until you neutralize all reinforcements) was removed (the alarm can even be turned off by using the binoculars and the soldiers will return to their default positions) and even though the areas were arranged, due to the room oriented nature of the transceiver messages, the developers forgot to move some of the messages along with it (for example, if you call Schneider in the area in front of the room where the gas mask is contained, he will tell you the location of the mine detector due to the fact that the location was originally a minefield in the MSX version). You can even talk to Schneider after his supposed death.
Hideo Kojima was reportedly unhappy with the quality of the NES version.
Japanese and Western differencesThe in-game dialogue in the NES version was translated by Konami in Japan, whereas the NES version's instruction manual was written by a writer Konami had in their US division, which were in charge of packaging and distributing their games. Konami of Japan had almost no editorial supervision over what the writer wrote in his manuals. Because of this, the writer would try to make his manuals as "humorous" as possible by taking any liberty with the game's plot.
In the manual for Metal Gear, the reader is led to believe that a middle-eastern terrorist named Vermon CaTaffy is the bad guy in the game and that Snake's commanding officer is named Commander South. However, no such names are featured in the game's dialogue. In the actual in-game plot, the main villain's identity is intentionally kept a secret to the player since the eventual plot twist has the player's commanding officer (Big Boss) turning into a traitor by revealing himself to be the leader of the terrorists. The writer of the NES manual ignored this plot twist by making a made-up villain that's not featured within the game.
Snake's Revenge, the "American" sequel to Metal Gear also suffered from a similar localization treatment. Snake's Revenge was actually a Japanese-made sequel to Metal Gear made with the western market in mind. At the time the game was made, Hideo Kojima wasn't planning on doing a Metal Gear himself. As a matter of fact, Kojima wasn't motivated enough to work on an actual sequel himself until he learned about Snake's Revenge from one of the game's programmers, who encouraged him to make a true sequel himself. Snake's Revenge continues the plot established in the first Metal Gear for the MSX and NES and even has an appearance by the actual Metal Gear mecha (which was replaced by a Supercomputer in the NES port of the first game).
In the in-game plot of Snake's Revenge, the player is sent to neutralize a terrorist group from an undisclosed hostile nation who are developing a new Metal Gear prototype. Like in the first game, Big Boss is revealed to be the eventual bad guy, who has survived the events of the first game after getting cybernetic implants. In the manual, Big Boss is never mentioned and another made-up villain by the writer (Higharolla Kockamamie) is described in the storyline. Snake's Revenge has even more banal attempts at humor, by describing one of the characters to be "related to Ginger from Gilligan's Island".
The writer of KoA's manuals did the same thing with several other Konami games, including The Adventures of Bayou Billy, Contra and Life Force, where liberties were taken with the manual for "humor" without any consideration of what the original designers intended.
In the original Japanese storylines, every Metal Gear game pits you against U.S. Special Forces who have become addicted to war and who decide to start a few of their own. Perhaps because that wouldn't play very well to a domestic audience, and perhaps because they were feeling creative and/or bored out of their gourds, Nintendo of America changed the storyline of the original NES Metal Gear game so that you were up against Third World, Islamic (if you read between the lines) terrorist Vermon Cataffy. Cataffy's name bears a not-coincidental resemblance to Muammar Gadaffi, the terrorist mastermind de-jour of the 70s and 80s.
Snake's Revenge, the 'unofficial' American sequel to Metal Gear, continued this trend by pitting you against Higharolla Kockamamie, which not coincidentally enough rhymes with Ayatollah Khomeini, another Islamic fellow the American public wasn't very happy with at the time.
Metal Gear was voted #53 in the Top 100 Games of All Time poll published by Game Informer Magazine (Issue 100, August 2001).
The game documentation included a map composed mainly of gameplay screenshots. Upon closer examination, you can tell the screenshots were taken from the original japanese 8-bit Nes version, thanks to the japanese character set and some slightly different graphics (such as trucks, etc.) which can cause some confusion in the game.