"OUTER HEAVEN is the name of heavily armed land in the depth of southern Africa where the dreadful weapon called METAL GEAR is developed. It is the mission of SOLID SNAKE, one of the members of secret army 'FOX HOUND' to sneak into OUTER HEAVEN and destroy METAL GEAR. GO AHEAD SOLID SNAKE!"
— Game description from the MSX2 version.
The very first installment in the Metal Gear series. Released in 1987 for the MSX2 computer platform in Japan and Europe, the original Metal Gear is considered to be one of the earliest examples of the stealth action game genre (although Castle Wolfenstein for DOS predates Metal Gear by a good six years, it's not a straight up action game), as well as the first commercially released game by Hideo Kojima.The game came into existence when Kojima's superiors, enamored with Capcom's arcade game Commando and noticing its success, asked him to create an overhead military shooting game for the MSX2. However, Kojima quickly discovered that a fast-paced shooter would be impossible on the MSX2, thanks to the system's own hardware limitations that limited the number of sprites that could be grouped together on the same horizontal plane before the sprites would start flickering (a hardware limitation that the MSX2 shared with the Nintendo Entertainment System, and which many old-school NES players are familiar with). Kojima then decided to retool the game around avoiding combat instead, and decided to base the game around stealth and infiltration.The player controls Solid Snake, a rookie member of special forces group FOXHOUND, who is sent on a mission to infiltrate the fortified state of Outer Heaven and destroy their top-secret weapon Metal Gear, a walking tank capable of launching nuclear missiles from any angle. The game's story is mainly remembered for the plot twist at the end that reveals that Snake's commanding officer, Big Boss, is the leader of Outer Heaven, which served as the foundation for future games in the series.Konami also produced an NES version, which was developed without the involvement of the original team (which would led to Kojima disowning the NES version in later years). While the plot is the same, the NES version lost a few gameplay elements that affected the overall difficulty: enemy guards no longer drop rations nor ammo when they're punched to death, there's no invincibility window when the player sustains damage (allowing enemies to easily bullrush the player to death in early stages), checkpoints are now based on the player's rank rather the current location, the higher alert mode was removed, (making it easier for players to escape from enemy guards by simply moving to the next screen), and enemy reinforcements now come in single file.The NES version also replaced a couple of the bosses: namely the actual Metal Gear itself was replaced by a Super Computer that Snake must destroy in its place. The level layout was also changed drastically: Snake begins his mission in a jungle prior to reaching the first base, the enemy transport trucks are now used as a means of getting around (due to the aforementioned lack of checkpoints) instead of setbacks, and the basement floor that connected the first two bases is now a separate building. The soundtrack of the NES version is a mix between rearranged music from the MSX2 version and new themes.For many years the NES version of Metal Gear was the only version of the game officially available in North America, since the MSX format was never commercialized in that region. The NES version sold surprisingly well in the U.S. despite the changes made, as players at the time were unaware of the original version. However, the later success of Metal Gear Solid would raise mainstream awareness of not only Kojima himself, but also of the MSX2 version and its Japan-only sequel Metal Gear 2: Solid Snake. The two games eventually got a proper worldwide release in 2006, thanks to their inclusion in Metal Gear Solid 3: Subsistence.
This game provides examples of the following tropes:
All There in the Manual: While the backstory is not quite as extensive as its sequels, the Japanese manual for the MSX2 version has character and enemy profiles that reveal details not actually mentioned in the game itself (like Schneider's motivation for leading the Resistance movement), as well as the complete specifications of Metal Gear itself. The manual also implies that, besides the unfinished message by Gray Fox, he also reported the items and weapons locations discovered in building one shortly before his capture. An English translation can downloaded here.
Ambidextrous Sprite: Played straight when Snake is unarmed, but otherwise averted when he's equipped with a gun. All of the enemy guards and the final boss have different sprites when facing left and right.
Artificial Stupidity: Guards won't notice you unless you're standing in a straight line directly in front of them. Even if you're standing just inches to their side. Even if you kill another guard in front of them (as long as you're using silenced firearm or punching them). This is especially egregious when you reach the checkpoint in front of Building No. 2, where you can kill a guard while wearing the enemy uniform and none of his buddies will know any better.
Gray Fox isn't too useful, even refusing to budge from his prison cell once freed. Later, Snake would claim that Fox was an active participant in the crisis and "showed him the ropes," much like how Snake mentors Raiden in Metal Gear Solid 2.
In Metal Gear 2, Schneider reveals to Snake that Outer Heaven was bombed by NATO, along with everybody else involved in the conflict. This causes many of Snake's allies to defect to Big Boss' side in the sequel, and Big Boss' personal charisma would become an enduring trait of the character.
Big Boss is utterly dismissive at the idea of Snake using a cardboard box to hide, which clashes with Big Boss' cardboard obsession in the later prequels.
Computer Equals Monitor and Frank's 2000 Inch TV: In the NES version, the "Super Computer" is in fact an oversized personal computer with a keyboard to match. Destroy the giant Zenith TV set, and the global thwart is thwarted.
Difficulty Level: The Subsistence version adds an Easy mode in addition to the original's difficulty, which increases the ammo and item-carrying capacity by twice the amount.
Dirty Coward: Coward/Dirty Duck hides behind POWs while fighting Snake. Even his name (both of them) spells it out.
The Dog Was the Mastermind: When the game was first released, Big Boss being the mastermind of Outer Heaven was a complete shock and appeared virtually out of nowhere. Although the player could get an early clue should they rescue the one POW in Building 3.
Dual Boss: The TX-11 twins, although the game treats their encounter less like a boss battle and more like an obstacle that needs to be dealt with (the boss theme isn't played when they're around, except in the NES version). The Twin Shot boss in the NES version is a more conventional example of this.
Early Installment Weirdness: No crawling. No radar. A transceiver that was completely room oriented. A straightforward, simple plot. A relatively realistic Quirky Mini Boss Squad. After playing this, Metal Gear 2 becomes amazing for how much closer it is to the later Metal Gear Solid games.
Elite Mooks: The jet pack-equipped Flying Army unit that appear on the rooftops of Building No. 1 and No. 2.
Event Flag: The NES version won't allow you to destroy the supercomputer without first rescuing the doctor.
The Faceless: All of Snake's radio contacts are never actually seen in-game with the exception of Big Boss. The Japanese manual for the MSX2 version has illustrations of all the main characters though.
Gameplay and Story Segregation: Retroactive example: in the sequels, the events of the Outer Heaven Uprising are described to be somewhat epic, but the game itself seems to be lacking in that regard (in fact, the way the events of the game are described in the sequels make it a variation of a noodle incident). It's largely for this reason why various fans are constantly demanding remakes of the MSX2 games, this game in particular.
Punching random walls to produce unusual sounds and blow them up? Frustrating, but a staple of games like this. Punching random doors which previously only opened with keycards so that you can open them? Not so excusable.
During the early portion of the mission, Big Boss tells the player to contact Schneider whenever a specific item is required in certain locations (such as the first gas-covered room or the first area with an electrified floor). The problem is that Schneider's frequency number is never given by anyone in the game; it's not even listed in the manual. If you play around with the transceiver in a certain area (namely in the corridor with the two security cameras after going through the very first elevator) you will eventually receive an incoming call from Schneider if you set the frequency to a certain number, but players who don't mess around with the transceiver as much are unlikely to ever figure out his number without looking it up secondhand (which is 120.79).
In the NES version, there are two maze areas in which the correct path is never given by any character. The correct path is the same for both mazes, which is: West, West, North, and West.
Heroic Mime: While Snake does have lines of dialogue, most of it is just the same three generic messages: one when he dials a frequency number on his radio, when he obtains a new weapon or item, and finally, one when he is in a moving truck. All of his conversions with the other characters are one-sided and the only time he ever says anything different is when he locates Dr. Madnar's empty cell in Building No. 1, and when he gives his final mission report in the ending.
His Name Is...: Schneider's transmission was cut just before he is about to reveal the identity of the Outer Heaven commander.
Hostage Spirit Link: Shoot a POW and your rank goes down. Justified in that your rank is a representation of how many POWs you've saved anyway.
Human Shield: Dirty Duck hides behind POWs, and shooting them causes a demotion.
The Key Is Behind the Lock: The card key required to access the prison where Gray Fox is being held is inside the prison itself. This requires Snake to get captured on purpose and breakout from said prison.
Lost In Transmission: How the events of Snake's mission starts. Gray Fox's final words in his final transmission before it was cut were the words "Metal Gear..."
Mercy Mode: If you get killed while setting the explosives on Metal Gear's feet, you can resume from the last bomb you set off, which is pretty convenient if you didn't have enough explosives when you first reached the room.
No Celebrities Were Harmed: The cover illustration is a blatant trace-over of a publicity still from The Terminator featuring Michael Biehn posing as Kyle Reese.
No Peripheral Vision: The guards literally have no peripheral vision whatsoever. Snake can run alongside them, run past them on the side, and stand next to them as long he wants. They'll never see him unless he's directly in front of one or is already being pursued. The NES version gives enemies better vision, being able to see slightly off what's directly in front of them.
Schneider, Diane, Steve, Jennifer and Dr. Petrovich. Subverted by Elen, whose full name is listed as "Elen Petrovich" in the Japanese MSX2 manual.
Metal Gear 2 gave two of those characters full names, Kyle Schneider and Dr. Pettrovich Madnar, essentially retconing "Pettrovich" from a surname to a given name. In the re-released versions, Madnar's full name was further changed to Dr. Drago Pettrovich Madnar (turning "Pettrovich" into a patronymic), while Ellen's surname was officially changed from "Pettrovich" to "Madnar" for consistency.
On Site Procurement: You're sent in with a radio and a packet of cigarettes. Anything else has to be scrounged.
Orwellian Retcon: Some of the characters were renamed in the re-released versions of Metal Gear, although the changes were not as extensive as in Metal Gear 2.
Dr. Petrovich now gives out his full name as Dr. Drago Pettrovich Madnar.
Likewise, his daughter Elen became Ellen Madnar.
Punch Packing Pistol: Started the grand tradition of the humble silenced pistol being your most useful weapon. Most of the other weapons in this game tend to be useful in specific situations (mainly boss battles).
Puzzle Boss: Metal Gear can only be destroyed by planting 16 explosives on its legs in a specific order. To make things worse, you have to guess where to put the last bomb.
Shout-Out: To Howard the Duck of all things. In the early versions, the boss that was later renamed Dirty Duck was known as Coward Duck. Also, a powerful android that was later renamed Bloody Brad was originally known as Arnold.
Taking You with Me: The Petrovich body double attempts to do this to Snake after the latter rescues him, via using a pit trap. It failed, though. Big Boss also attempts to do this in the final boss fight.
Universal Ammunition: Each ammo box contain 20 handgun bullets, 20 machine gun bullets, 10 grenade launcher rounds and 2 rocket rounds.
Unwinnable by Design: See Hostage Spirit Link or Video Game Cruelty Punishment concerning demotions. If you get a demotion in some situations, you will not have enough ammo to destroy certain bosses (or even to obtain an item needed to complete the game). This is particularly egregious during the Coward Duck boss battle, where he shields himself with three hostages. Killing all three will demote Snake to the starting rank. There might not even be enough unsaved POWs by that point to restore the required four-star rank.
Video Game Cruelty Punishment: Killing a single POW will demote the player to their previous rank. Itís possible for the player to work his way back to his previous rank if there are enough POWs still left to save, but killing certain POWs (like Ellen or Jennifer's brother) will make the game unwinnable.
What Happened to the Mouse?: In the NES version, Snake is shown parachuting into Outer Heaven with three other soldiers. They are never seen nor mentioned again. These were probably supposed to be Schneider, Diane, and Jennifer, Snake's on-field contacts, likely establishing how they ended up on the field with Snake. However, this is never stated as such and contradicts with the implication that the Resistance movement was operating locally before Snake arrived (with Diane working from her own home with her brother Steve and Jennifer as an inside agent within Outer Heaven's medical staff).