Snake's Revenge is an alternate sequel to the original Metal Gear released exclusively for the Nintendo Entertainment System in 1990. It was the first Metal Gear sequel made by Konami, produced without the involvement or consent of the original game's creator, Hideo Kojima (in fact, Kojima even remained unaware that the game even existed until one of his co-workers brought it up during a casual conversation), and in response to the success of the NES version of Metal Gear in the overseas market. Despite Kojima's lack of involvement, the existence of Snake's Revenge would inspire Kojima to design his own sequel to his game, resulting in the creation of Metal Gear 2: Solid Snake, relegating Snake's Revenge to non-canon status.
Three years after the Outer Heaven incident, FOXHOUND has learned that a nameless hostile nation has obtained the plans for Metal Gear. Solid Snake is called back into action to infiltrate the enemy territory. With the help of two new FOXHOUND members, weapons expert Nick Myer, infiltration specialist John Turner, as well as a double agent named Jennifer, Snake learns that the enemy have not only mass-produced the original Metal Gear model, but are now testing a new upgraded prototype called "Metal Gear 2."
Snake's Revenge is pretty similar to the original Metal Gear in terms of game design, although it is much closer to the original MSX2 version than the NES version. This time, Snake has an option to switch between his punches or using a knife for close range attacks (the latter allows him to kill enemies in one stab). In addition to the regular overhead areas, Snake's Revenge also feature several side view segments akin to Konami's own Rush'n Attack.
Snake's Revenge features examples of:
- All There in the Manual: The packaging and manual states that the Big Bad is a dictator named "Highrolla Kockmamie" (which is actually a play on the Iranian leader Ayatollah Khomeini). However, he's only mentioned in the packaging and manual and doesn't appear in the game itself. The Big Bad of the game is actually Big Boss. Curiously, despite the fact that Snake's Revenge is clearly intended to be a Metal Gear sequel, the manual and packaging description actively avoids using the name "Metal Gear" at any point, going as far as to refer to the enemy's ultimate weapon as the "Ultra Sheikh Nuclear Attack Tank".
- Alternate Continuity: Although, it wasn't intended to be one at first.
- Attract Mode: A diagram of Metal Gear 1's specifications.
- Black Dude Dies First: Subverted. Nick is the only member of Snake's support crew who is confirmed dead by the end of the game, but it happens just before the final battle. John disappears much earlier and we never get to find out what truly happened to him, after he gets captured in the beginning before being replaced by an impersonator.
- Blatant Lies: An imposter posing as John Turner tells you "There is no trap on the train". Turns out that there are traps.
- Cable-Car Action Sequence: The last base prior to reaching the enemy's fortress consists of three buildings that are connected by cable cars. To go from one building to the next, Snake must hitch a ride atop one of these cable cars, and avoid being spotted by the enemies inside the car during the side scrolling transition sequences.
- Canon Discontinuity: Produced without the involvement of series' creator Hideo Kojima. He would go on to develop Metal Gear 2: Solid Snake as the official sequel to the MSX2 original. Snake's Revenge never even had a Famicom release.
- Dynamic Difficulty: The number of enemy soldiers that appear during alert phases increases by two for each promotion the player gets. In other words, the higher Snake's rank becomes, the more reinforcements he'll face when spotted by the enemy.
- Hostage Spirit Link: Averted. Unlike the original Metal Gear, hostages are immune to the player's bullets.
- The Key Is Behind the Lock: The keycard that opens the entrance to the first base is inside the base itself. As a result, the only way Snake can infiltrate the base is by using an ally as a decoy.
- Locomotive Level: After the first desert compound, Snake must hitch a ride on a train to rescue a captured ally.
- Mission Control: Averted. Snake's radio contacts consists of two other field agents (John and Nick), a double agent in the enemy's main base (Jennifer), and the nameless helicopter pilot who drops him off at the beginning of his mission.
- One-Winged Angel: After Big Boss' initial form is defeated, he transforms into a cybernetic behemoth who claims that he has no weak points. It is also to be noted that this was the only Metal Gear game to utilize this until Metal Gear Rising: Revengeance was released years later. note
- Permanently Missable Content: If you get aboard the ship without picking up the suppressor or the sub machine gun, you will not get another chance of the game (at least not until the second desert compound, which offers a spare suppressor). And woe to those who forget to pick up the mine detector before sinking the ship, as the next area starts in the middle of a minefield. The train section is at least generous enough to allow you to pick up any essential items you might've missed out on, after defeating the boss before being dropped off to the next area.
- Point of No Return: Unlike the original Metal Gear, Snake's Revenge doesn't allow backtracking once the player reaches certain areas, particularly when infiltrating the cargo ship carrying the mass produced Metal Gears after leaving the first enemy base, and later on when Snake must hop aboard a train transporting a captured ally.
- Random Drop: Brought this feature back after the first NES game removed it.
- Reverse Mole: Jennifer ("Your Person") is helping out Snake from inside the enemy's base. Her cover is blown and she is captured by Big Boss just before the final battle.
- Revenge of the Sequel: The game's title makes little sense, considering it is Big Boss who wants revenge against Snake for turning him into a cyborg. This was years before Big Boss was revealed to be the original Snake whom Solid was cloned from.
- Suspiciously Specific Denial: At one point, a captured ally tells Snake via radio that his present area has no enemies or traps. He turns out to be an enemy spy.
- Taking You with Me: The final fortress has two fake hostages who will blow up if Snake attempts to rescue them. Also, some of the enemy reinforcements are literal suicide bombers.
- Token Minority: Nick is the only black guy among Snake's support crew.
- Truth Serums: An actual play mechanic unique to this game. Certain rooms are inhabited by enemy officers who don't offer any resistance against Snake, but will refuse to divulge any information to him, unless the player uses a "Truth Gas" canister, in which case the officer will reveal a piece of information vital to Snake's mission. Interrogated officers are counted towards the player's promotion alongside rescued hostages.
- Unexpected Gameplay Change: The side view segments.
- Universal Ammunition: Like in the original, ammo boxes provide bullets for all of Snake's firearms (the handgun, the machine gun, and the shotgun). Averted with the flare gun, which can only be loaded with flare bullets.
- With This Herring: Subverted. Snake begins his mission already equipped with a knife and a handgun (which are also Snake's main weapons during side scrolling segments), although he still needs to procure a suppressor (which is provided by Nick after infiltrating the first base) and all the other weapons on his own.
- The Very Definitely Final Dungeon: The enemy's headquarters is a large medieval castle, a huge contrast to the military bases, vehicles, and outdoor environments that the player infiltrates prior to that point.
- What Happened to the Mouse?: John is never seen again after Snake defeats his impersonator and is declared MIA in the ending. It is unknown whether he was killed or kept alive after his capture.
- Your Princess Is in Another Castle!: Snake succeeds in sinking the enemy's shipment of Metal Gears only to find out that the enemy have already completed the prototype for the new model, Metal Gear 2, in their headquarters.