History YMMV / MetalSlug

** Special mention should go to “Final Attack” in ''Metal Slug 5'', which is so badass that ''VideoGame/SuperSmashBrosUltimate'' not only uses this version (not exactly from the most revered ''Metal Slug'' game) but ''doesn’t alter or remaster it at all'', unlike the other to ''Slug'' tracks. It’s just that perfect.

*** Not a weapon or level completion, but there's also his '''WHOA-HO! BIG!''' (along with '''UH-OH! BIG!''') in the occasions where your character eats enough food to become fat, to the point it has become very popular in fanart circles that usually depicts weight gain or inflation fanart out of Fio, Eri and Nadia, the former of the three is a very popular MsFanservice BespectacledCutie who's a reluctant BigEater (who's gotten the most fanart treatment with Eri being a close second, though it helps they were the first ever playable ''females'' of the cast), and the latter of the three is the biggest BigEater of the cast (as either the title of the fanart in question or the comments of said fanart will have them blurt out one or both of the titles).

** Sol Dae Rokker from ''Metal Slug 3''. Its only weak point is the small red jewel in its forehead and due to the boss moving constantly it can be quite difficult to shoot. The boss also levitates way above the player, meaning that you can't harm it with grenades. Most of its attacks aren't a big deal, but ThatOneAttack where it spreads a flurry of yellow beams in random patterns is a nightmare to dodge, specially after the boss is enraged.

** [[ActionGirl Fio and Eri]] are two the most popular among the main cast [[{{Meganekko}} for]] [[BadassAdorable various]] [[MsFanservice reasons]].

**

** [[MoreDakka Fio]] [[{{Meganekko}} for]] [[BadassAdorable various]] [[MsFanservice reasons]].

** Leona snaps ''Metal Slug XX'' like a twig with her Moon Slasher technique, which does about twice as much damage as a grenade and erases enemy atta, with ''''"infinite uses and no cool down.''''' Having a weaker AllYourPowersCombined version of the other characters' bonuses doesn't hurt, either.

** Leona snaps ''Metal Slug XX'' like a twig.

*** Not a weapon or level completion, but there's also his '''WHOA-HO! BIG!''' (along with '''UH-OH! BIG!''') in the occasions where your character eats enough food to become fat, to the point it has become very popular in fanart circles that usually depicts weight gain or inflation fanart out of Fio, Eri and Nadia, the former of the three is a very popular MsFanservice BespectacledCutie who's a reluctant BigEater (who's gotten the most treatment with Eri being a close second), and the latter of the three is the biggest of the BigEater of the cast (as either the title of the fanart in question or the comments of said fanart will have them blurt out one or both of the titles).

** There's also [[{{Meganekko}} Fio]], the series' resident Moe character.

*** Not a weapon or level completion, but there's also his '''WHOA-HO! BIG!''' in the occasions where your character eats enough food to become fat.

* BigLippedAlligatorMoment: The sinking gun hitting the fishman in the end of ''Metal Slug 3''. [[WhatCouldHaveBeen Was supposed to be subverted]] in ''Metal Slug 4'', where fishpeople where planned to be the main enemies of the game or enemies exclusive to an underwater city mission [[note]]The former idea based on [[https://www.youtube.com/watch?v=-0PgNJMP3G4 this French video]] while the latter is based on an interview in ''Metal Slug Anthology''[[/note]], but went under due to the staff losing interest in the idea and by SNK's bankruptcy at the time (He does make an appearance as an AprilFoolsDay unit in ''Attack'', over a decade after the fact).

* FountainOfMemes: The announcer, who regularly belts out incredibly hammy quotes whenever you pick up a new weapon on the field.
** Allen O'Neil also fits as he's a big, muscular guy toting a GatlingGood machine gun, and constantly taunts and boasts to you. And he seemingly returns from every death, even in cases where he should have died for good.

** An interesting case in which any "perfect port" of ''Metal Slug 2'' is accused to be terrible due to its glaring slowdown issues while any other port that fixes the slowdown is [[PolishedPort considered superior]].

** Subverted with ''Terrifying 9/11'', a bootleg [=GameBoy=] Color port of ''Metal Slug 1'' [[note]]Although there are theories that it may be an actual cancelled port due to the unique programming quirks and consistency with the original source unlike other bootlegs[[/note]], which is fully functional despite its shoehorned UsefulNotes/TheWarOnTerror imagery.

* SeasonalRot: ''4'' is generally agreed to be the weakest in the main series. Reasons include recycling ''a lot'' of assets from the previous games (to the point that most bosses are a mishmash of previous bosses in both looks, mechanics and gimmicks), Eri and Tarma being inexplicably [[DemotedToExtra demoted to mission control NPCs]] and [[ReplacementScrappy replaced with newcomers Nadia and Trevor]], and the very few innovations being features that players weren't enthusiastic about (The Metallish Combo System, transition cutscences between missions) or downright disliked (Nadia and Trevor again). It's rather telling that the only thing this game introduced that carried on in future installments was the Two Machineguns.

** The Evil Spirit Incarnate's wings detach from its body when it readies its scythe.

%%* FountainOfMemes: The announcer, as seen below.
%%** Allen O'Neil also counts.

** An interesting case in which any ''perfect port'' of ''Metal Slug 2'' is accused to be terrible due to its glaring slowdown issues while any other port that fixes the slowdown is [[PolishedPort considered superior]].

** [[JokeWeapon Stone]] is well... a stone. That doesn't even explode on impact.

** Much like ''VideoGame/TheKingOfFighters'', ''Metal Slug'', thanks to being included in SNK's affordable 100-in-1 arcade boards, became widely popular in Mexico and Latin America in general. In any video or article regarding ''Metal Slug'', there will be a hefty amount of Spanish comments.

* SugarWiki/AwesomeArt: The amount of detail in the sprites is unprecedented. The games do run at only 30 FPS as a result (with the first two outright chugging along when the enemies and their shots start flooding the screen), but it's a fair compromise for the amazing animation of the series' many characters.

* BigLippedAlligatorMoment: The sinking gun hitting the fishman in the end of ''Metal Slug 3''. [[WhatCouldHaveBeen Was supposed to be subverted]] in ''Metal Slug 4'', where fishpeople where planned to be the main enemies of the game or enemies exclusive to an underwater city mission [[note]]The former idea based on [[https://www.youtube.com/watch?v=-0PgNJMP3G4 this French video]] while the latter is based on an interview in ''Metal Slug Anthology''[[/note]], but went under due to the staff losing interest in the idea and by SNK's bankruptcy at the time.
** He does make an appearance as an AprilFoolsDay unit in ''Attack'', over a decade after the fact.

* FanNickname: Prior to ''Metal Slug Defense'' and ''Metal Slug Attack'', a good number of enemies, bosses, and characters post ''Metal Slug 3'' did not have official names, so fans came up with their own names. Due to the large time gap before their actual names are given, [[WordOfDante some treat these fan names as official]]. Some of these fan names showed up in the officially licensed ''Metal Slug: The Ultimate History'' artbook, although they are also disproved by SNK.

* FountainOfMemes: The announcer, as seen below.
** Allen O'Neil also counts.

** The final mission of ''Metal Slug 3'', which is the longest mission in the entire series.
*** To make things even worse, if you're playing on the Xbox port, you have limited continues, and if you use one, you'll start back all the way from the beginning.

* AuthorsSavingThrow: ''Metal Slug 5'' addressed many of the complaints players had about ''4'', such as giving [[ReplacementScrappy Nadia and Trevor]] the boot and making Eri and Tarma playable again, as well as introducing quite a lot of new backgrounds, sprites and unique bosses in order to give the game a more original feel instead of reusing assets from previous games.

** Allen O'Neal is fairly popular, mainly because of the BossBanter.

** Allen O'Neal also counts.

** Allen O'Neal is no slouch in this department either.

** The "Metallish" combo system (where medals are given by shooting enemies and a fever time appears when collecting a special emblem) in ''Metal Slug 4'' is regarded as very confusing. The medal system is unituitive, and the combo meter stops when a player goes into a Slug. It was revamped to a simpler combo system in ''6'' (where shooting enough enemies/obstacles will increase the score multiplier until coins spew out for a short time) and has retained since then.
** Metal Slug 6 gives every character its own special abilities, which is neat weren't for the fact that with the exception of Fio, overall ammo from picking special weapon is reduced significantly, forcing most players to contend with the pea-shooter pistol if there is no driveable vehicles.

** Allen O'Neal from Metal Slug and ''Metal Slug 2/X''. Yeah, this guy is extremely hard to defeat if you don't know how to predict his attacks. He can shot with his Machine Gun and if you try to move to the other side he just use a grenade towards you!

** The bosses of stages 3 and 4 of ''Metal Slug 6'' are much more durable and nasty than the first two bosses were. Both take ridiculous amounts of punishment and have nigh-unavoidable attacks. Expect to use a lot of credits.
*** The stage 3 boss, Brain Robot deserves even more special mention. Firstly: You're moving to your right, constantly, which means it feels awkward reaching around and shooting at the robot, not to mention the controls automatically face you to the right if you try to jump to the right to dodge something. This means it will take forever to kill it. Secondly: once it loses some HP, it will keep attacking non-stop with the electric brain balls that move forward, stop, then aim for you. Even with the obvious pattern you'll be killed repeatedly. It gets especially bad when it combines this with the "shock the floor" attack where the only safe spot happens to be a very small box you can stand on, meaning you either have [[SadisticChoice very little space to avoid the balls, or land on the electrified floor and die instantly]]. The "vulcan fix" skill is very useful here (hold down the shooting button to keep shooting in a fixed direction). Also, don't even try to bait it into using its melee attack too much, or it will [[TurnsRed get pissed]] and keep swinging his electrified arms reducing the safe zone to a ridiculous minimum!

* OvershadowedByControversy: Non-fans tend to know about ''Metal Slug 4'' because the president of Mega Enterprise (who developed the entry with permission from Creator/{{SNK}}), Lee Sang, was charged of misdemeanor by the South Korean police who attempted to arrest him, and escaped to China, rather than anything about the game itself.

** The "Metallish" combo system (where medals are given by shooting enemies and a fever time appears when collecting a special emblem) in ''Metal Slug 4'' is regarded as very confusing. Not all of the time the player will earn medals, and the combo fever stops when a player goes into a Slug. It was revamped to a simpler combo system in ''6'' (where shooting enough enemies/obstacles will increase the score multiplier until coins spew out for a short time) and has retained since then.
** Metal Slug 6 gives every character its own special abilities, which is neat weren't for the fact that with the exception of a certain character, overall ammo from picking special weapon is reduced significantly, making most players have to content with the pea-shooter pistol if there is no driveable vehicles.

** The Flame Shot in [[EarlyInstallmentWeirdness the first game]], while useful for weeding out multiple Rebels, is close to useless for taking down machinery. The [[TookALevelInBadass new version]] for ''2'' onward is worth picking up.

* SeasonalRot: ''4'' is generally agreed to be the weakest in the main series. Reasons include recycling ''a lot'' of assets from the previous games (to the point that most bosses are a mishmash of previous bosses in both looks, mechanics and gimmicks), Eri and Tarma being inexplicably [[DemotedToExtra demoted to mission control NPCs]] and [[ReplacementScrappy replaced with newcomers Nadia and Trevor]], and the very few innovations being features that players didn't really cared for (The Metallish Combo System, transition cutscences between missions) or downright disliked (Nadia and Trevor again). It's rather telling that the only thing this game introduced that carried on in future installments was the Two Machineguns.

* SugarWiki/DevelopmentHeaven: How many run and gun shooters were there back then--or even today--that do as much random stuff as this? Enemy conversations, animated chin movements, fifty different ways of watching the exact same tank explode? Nobody asked for all this: [[Creator/{{SNK}} somebody]] just really wanted to make a detailed shooter.
** If you have the chance, try going to the first stage of the first game. Early on, you get the Flame Shot and you can pass through a destroyed part of an airplane fuselage. Firing it will actually lighten up the area around you. This, in a fully 2D game with no added lighting effects of any kind, is just another mark of how incredibly detailed a game ''Metal Slug'' is.
** Oh, and the first stage of ''Metal Slug 2/X''? The Arabic writing in the background is not only accurate, but silly as per series standard.

* {{Squick}}: The zombies infect civilians and the player characters by [[ZombiePukeAttack vomiting/spraying infectious fluids on them]], accompanied by a disgusting-sounding "glorp" sound effect when they release the puke. Two variants (female zombies and one of the male zombie civilian types) actually [[VomitIndiscretionShot puke the stuff up]]. The scientist zombies top that by ''pulling out their own intestines'' and squeezing them to expel the vomit.

** Oh, and the first stage of ''Metal Slug 2/X''? [[http://turntoch3.com/megashock/reviews/extra_mslug2/ The Arabic writing in the background is not only accurate,]] but silly as per series standard.

** [[MoreDakka Fio]] [[{{Meganekko}} for]] [[BadassAdorable various]] [[MostCommonSuperpower reasons]].

** ''Metal Slug 6''. Most point of contention are concerning about how short the game is compared to the previous games as well as reduction to special weapon ammo (see ScrappyMechanic below). Either way though, it is generally agreed that it is where the series got out of its DorkAge.

* DorkAge: The Noise Factory era (who developed ''4'', ''5'', and ''Advance'') is the point where opinions were widely split, specifically regarding the games' level design, mechanics, and the reuse of assets from previous games.