Metal Gear Acid (stylized as METAL GEAR AC!D on the logo) is a Metal Gear spinoff released for the PlayStation Portable in 2004. The first game in the franchise released for the PSP, rather than being a stealth-action game like its console counterparts, ACID (or MGA) is a turn-based strategy game featuring a card-based combat system in which the player's weapons, equipment and abilities are determined by the player's deck. While the story is set in an Alternate Continuity and has no bearing in the main Metal Gear Solid canon, the player's cards feature characters, items and other elements from the first three MGS games (and also from the preceding Metal Gear games), as well as other KCE Japan titles released at the time.
In 2016, a terrorist group has hijacked a plane using a chemical weapon, threatening the lives of its passengers, with U.S. Presidential candidate Viggo Hach among the hostages. The terrorist demand that the U.S. Government hand over the "Pythagoras", a top-secret project developed in the South African country of Moloni. With the Moloni government refusing to cooperate, the US sends FOXHOUND member Solid Snake to infiltrate the Lobito Physics and Chemistry Laboratory in Lobita, where the Pythagoras is being kept. With the help of Teliko Friedman, a member of the FBI's Hostage Rescue Team that was sent to retrieve the Pythagoras, Snake learns about the true nature of the Pythagoras.
A sequel was released in 2005 titled Metal Gear Acid 2 (or METAL GEAR AC!D2), also on PSP, featuring more than twice the amount of cards, cel-shaded graphics, a new Arena Mode, and an add-on for the PSP called the Solid Eye that allows the player to view the game in 3D.
Set sometime after the events of the first Acid, Snake (now a member of a Resistance force) reluctantly agrees to infiltrate a facility located in an island off the coast of North America, owned by a military contractor named SaintLogic Inc. There, he finds out that SaintLogic has been involved in the development of a new Metal Gear tank.
Following the release of both Acid games, along with Metal Gear Solid: Digital Graphic Novel, Konami decided to produce a more traditional Metal Gear for the PSP titled Metal Gear Solid: Portable Ops.
This game provides examples of the following tropes:
- Absolute Cleavage: Take one look at Takiyama...
- Alternate Continuity: The AC!D games go in a different direction than the parent Solid series, and have no bearing on its plot.
- Arbitrary Skepticism: Snake isn't convinced Alice is actually psychic, even though such powers exist in the Metal Gear universe. He turns out to be right... at least partially. Alice was really just familiar with the layout of the base, but there was some sort of reincarnation of children involved. It's complicated.
- Snake, to Venus' dousing, for the same reasons. He's also a bit skeptical of the second-to-last Boss's psychic powers. Until he walks on the ceiling.
- Art Shift: The in-game graphics in the first MGA were not that much of a departure from the mainline MGS games at the time, despite the use of anime-like character portraits. MGA2 on the other hand, uses a cel-shaded style that makes it stand out from the rest of the series.
- Awesome, but Impractical: A rare for-the-villains version. Chiagdiel, a Viet-Cong psychic ninja with a grenade launcher, whenever he walks on the ceiling, is a stationary target and easy to whack with, say, a rifle. Or a good old fashioned handgun. Hitting him with even a pistol will cause him to fall off and take extra damage.
- Big-Bad Ensemble: Leone, William Flemming/Gary Murray Lena Arrow and Alice Hazel.
- Brainwashed and Crazy: Venus. For starters, she attempts to kill Snake nearing the end because Wiseman ordered her to. It is also heavily implied that she couldn't refuse his orders as he removed her free will.
- Snake and the other test subjects were this, but gained amnesia. Venus was one of the more "successful" ones.
- Bulungi: The Moloni Republic
- Clear My Name: Leone's last words, "It wasn't me," are to clear his name.
- Snake also has to do this in MGA2. Well, technically - Dalton's blackmailing him into investigating SaintLogic, and if he does so, he'll get pardoned and will be a legal immigrant to the US.
- Continuity Nod: Nearly all of the card decks, for one. You can even shoot guns that were in the original Metal Gear games - in sprite form, no less.
- On a side note, some weapons (like the PTRS/PTRD, RPK, et cetera) made their way into Metal Gear Solid: Peace Walker. The XM8 and XM25 also made their way to Metal Gear Solid 4.
- The Tobidacid is referenced in MGS4 during a codec conversation with Otacon, where it is said to be one of Solid Snake's childhood toys.
- Venus and Teliko are recruitable, hidden soldiers in Portable Ops.
- Dr. Koppelthorn, the main antagonist in MGA2, was previously mentioned character in Ghost Babel (where his name was often mentioned by Mei-Ling), as well as in MGS2: Substance (where he is the inventor of a VR simulation machine in the Snake Tale "External Gazer").
- In Metal Gear Solid 3, rations were used to replenish stamina, rather than to refill the health gauge as in the other games. However, in the Ac!d games, since there is no stamina, rations heal again. The description for the "Ration" card in the second game says that in the old days, soldiers used to think that rations restored stamina.
- Defog of War: There are multiple cards dedicated to this, though they all have certain drawbacks, like having a high cost draw.
- The Dog Bites Back: After Vincent is defeated by Snake and Venus, he learns that Rodzinski is leaving the facility on his getaway chopper and leaving the security forces to take the blame. After a particularly big Kick the Dog moment from Rodzinski, Vincent orders his soldiers to shoot him down, with the soldiers obeying the command without hesitation, presumably agreeing with him about why they should do so.Security Forces: Major! We've located Mr. Rodzinski! He's about to leave in a chopper, sir.
Vince: Put him on.
Rodzinski: What do you want? Wait. Vince, is that you?
Vince: Mr. Rodzinski. What are you doing?
Rodzinski: I'm getting the hell off this island!
Vince: But what about Koppelthorn?
Rodzinski: You think I give a damn about that lunatic?! The ICC has decided to carry out their investigation! My deal with those goddamn politicians was worthless! After all the money and assets I invested in this, they abandoned me at the first sign of uncertainty! The ICC is sending an investigation team to the island next week. At this point, they won't let me go even if I get them the Lucinda File. The deal is off, and now I'm facing criminal charges. If I'm tried under the Serena national judicial system, I could be executed!
Vince: ... What are you going to do?
Rodzinski: Run like hell! What other options do I have? I can't set foot in this country ever again. ...I never believed this day would come.
Vince: So you're leaving this whole mess here with us?
Rodzinski: Spare me the sad story, Vince. You're the big boys. Take care of yourselves for once!
Security Forces: Awaiting your orders, sir.
Vince: Shoot the bastard down.
Security Forces: Yes, sir.
- Even Evil Has Standards: In the second game, Vince is disgusted by his employer's lack of honor trying to evac the site with its personnel left behind when it's clear there's no stopping Koppelthorn and actually orders his men to kill him by blowing his helicopter out of the sky. Before he dies, he requests that Snake and Venus let the rest of his men live.
- Fight Like a Card Player:
- In game, though, he often accidentally kills his own men via rocket launcher or thrown barrels.
- Fog of War: Some levels are in "Search Mode", which functions as this for the player. Even when it's not in effect, though, when the guards aren't on alert, they basically have their own Fog of War.
- Gaiden Game: These games don't have the "Solid" in their titles for a reason: They're totally not in continuity with the MGS titles, despite that they reference them constantly through the cards. Snake is still a legendary solider with a mysterious past, but there's no Liquid, no FOXHOUND, no Big Boss. This allows the creators to give Snake an entirely new mysterious past to mess with him. In addition, Snake apparently died in-between AC!D and AC!D2.
- Gameplay and Story Segregation: Varies. The first rendered cutscene in the first game shows Teliko in a mission, with her movement and actions controlled by the same cards and grid that the player uses to play, and Roger later tells Snake about the cards, referring to them as, well, cards. But later, cutscenes are more conventional, and in the second game the cards are just referred to as "techniques" that the amnesiac Snake must relearn, as a form of nanotechnological data packets that are released into his brain.
- Lampshaded several times in the sequel - Dalton complains about the CARD system's explanations being confusing and jargon-filled when Wiseman rambles on about them, and while Lucy/Metal Gear gloats, Snake and Venus calmly discuss Metal Gear's "glitch" that allows you to see its drawn cards.
- During the fight with Venus, you can kick her off the ledge if you're lucky, allowing you to bypass the entire battle. She's back up on the railing in the cutscene though.
- Gotta Catch 'Em All: There are a lot of cards to collect... or buy. Since you only get three cards at a time upon a purchase and they're randomly determined, trying to get all of them is an exercise in utter frustration.
- Jerkass: Venus to Doc Takiyama... even after Venus rescues Takiyama from arrest.
- Jerk with a Heart of Gold: Although she was somewhat nicer to her in the latter event.
- Jiggle Physics: Present in the second game, and very noticeable since everyone's jiggle physics are... activated every time a new scene is rendered. They are extremely wobbly.
- Fun fact: Snake's web belt has the same boobie physics as Venus' and Takiyama's.
- Jigsaw Puzzle Plot: The first game manages to be somewhat more confusing than the Solid series. The second game is easy to follow (which is not to say it doesn't get a little weird).
- Kudzu Plot: To a lesser degree than in the Solid series, but it does get complicated at times. Lampshaded in 2 - Dalton struggles to keep up.
- Large Ham: The Kerotan who advertises new card packs.
- CHRONICLE CHRONICLE CUH-RONICLE!!!! ...PACK!
- Long Song, Short Scene: The main theme from the original MGS by TAPPY is played all-too-briefly during an advertisement for the MGS1 Pack in MGA2. The theme has been absent in subsequent Metal Gear games since then (starting with MPO) due accusations of plagiarism, making MGA2 the only PSP game in the series where it is played.
- Love Makes You Evil: Koppelthorn's entire reason for going batshit insane on his own facility. To some extent, Lucy's motherly drive for her ungodly mutants drives her to use Chaioth to make the world a better place for the test subjects.
- Mirror Boss: The final boss of Metal Gear Ac!d 2 is Venus herself, who draws the exact same cards as you do in your deck, but at an increased rate. You're going to have to play very cleverly to gain an advantage.
- Or, since she uses EXACTLY the same cards you do, fill your deck with movement and healing cards, position yourself towards the edge of the area facing the entrance next to the pit, get Venus right next to the edge, and punch-punch-kick her off for an easy victory.
- No Fourth Wall:Snake... er, Hans: Hey, come on! Don't change my name in the text box!
- Snake and Venus calmly discussing the final boss's weakness as it rants on and on about her motivations.
- Nostalgia Level: The Metal Gear KODOQUE/Pythagoras fight in the second game.
- Somewhat played with in MGA2's Arena Mode: The levels are based on MGS, MGS2, and MGS3, but aren't based off any one level. On the other hand, you can fight Liquid Snake, Revolver Ocelot, Vamp, Fortune, The End, The Boss, Venus and Teliko (The first and last can kill you in a single turn using a SOCOM which sometimes hits up to twenty times!). The enemy teams in arena mode always contain two people and are not randomly generated. Sometimes you'll get seemingly strange pairings (like two Telikos) but other times you get the standard pairings (e.g. Revolver Ocelot & Liquid Snake).
- Old Save Bonus:
- If you have photo save files from Metal Gear Solid 3: Subsistence, you can connect your PSP to your PS2 and view the pictures in 3D using the "Solid Eye" viewer in Metal Gear Ac!d 2. Additionally, you can import a limited number of cards from the first game into your deck in the second game.
- Both Ac!d games also unlock Teliko and Venus in Metal Gear Solid: Portable Ops.
- Older Than They Think: Invoked. The in-game commercial for the Chronicle Pack in the first Acid has the announcer reminding viewers that "Metal Gear wasn't always in 3D."
- One Dose Fits All: Any tranquillizer weapon will be equally effective on any guard, regardless of their size.
- Only Mostly Dead: Characters can take a lot of punishment, even being run over by trains, and still be revived on their own as long as there's another party member still alive.
- Mooks, on the other hand...
- Pacifist Run: Much, much harder, especially thanks to the range of tranq weapons, how plentiful lethal weapons are, and CQC's tendency to knock someone off a ledge... with lethal results. Still somewhat encouraged by Dalton, who will mention early on how many people you've killed so far and will note that you will be killed if you are caught, and Vince, who later on asks that Snake and Venus spare some of his soldiers, but beyond that, there's no Videogame Cruelty Punishment, aside from not getting as many bonus points or cards as you do with no kills.
- Parrot Exposition: Mostly absent from both games, but lampshaded in the second game.Dalton: Huh? Do you know anything about it?Snake: No... I just felt like I should say that.
- Private Military Contractors: SaintLogic Inc. uses mercenaries as guards.
- Psycho Prototype: All of the Test Subjects in the second game, fulfilling the role of Quirky Miniboss Squad. They include a giant cyborg ape who can shoot his arms at you (and regrow them!), a hypnotist dressed as a traditional Japanese... something... who likes to walk on the ceiling and wielding a grenade launcher, and a man holding a giant fuel container which he drinks out of to breathe fire.
- Riding the Bomb: In the ending for Ac!d 2, Snake ends up using the destroyed Metal Gear's missile launching ability to escape by cramming himself into a dummy warhead. It broke every single bone in his body - but he healed, thanks to his status as a super soldier.
- Slasher Smile: Harab Serap, the pyromaniac boss of AC!D2.'
- Theme Naming: The names of the Test Subjects and the Metal Gear itself in MGA2 all come from the Kabbalah.
- Those Two Guys and that Girl: The pilots and Consuela, who accompanied Snake to the US before getting caught. They're reunited at the end, but are absent for most of the game (besides some "encouragement" by Dalton and Snake.)
- Three-Dimensional Episode: The second game can be played in 3D, and comes with a "Solid Eye" viewer (a box with separate eyeholes for each half of the screen which shares its name with Old Snake's optical eyepatch from MGS4). Also used for viewing pictures taken from MGS3 and Subsistence in 3D... usually, those of EVA.
- Tomato in the Mirror: "Snake" from Acid 2 is actually a clone from the original Acid, who supposedly died between the events of both games.