History VideoGame / MetalSlug

*** After defeating Allan O'Neil, you're [[UnusableEnemyEquipment unable to claim O'Neil's machine-gun]] for yourself, for no given reason. This is changed in later games where O'Neil's dropped weapon can be collected (equivalent to a fresh Heavy Machine Gun pickup).

* CrooksAreBetterArmed: Zigzagged: your team of mercenaries come with a pistol and supply of small grenades against whole infantries. Even if you can get HEVEE MASHINE GUN or RAWKET LAWNCHAIR and the various Slugs later, your enemies will still have a lot of things under their sleeves. DeathOfAThousandCuts applies, though, so with enough shootings they'll all fall down.

* CompilationRerelease: ''Metal Slug Anthology'' on UsefulNotes/PlayStation2, [[UsefulNotes/PlayStationPortable PSP]], and UsefulNotes/{{Wii}} collects the first seven games in the series (first game through ''6'' and ''X''), though it misses the two Platform/NeoGeo Pocket games, as well as ''Metal Slug Advance'' and ''Metal Slug 3D'', and the games suffer from slowdown.[[note]]which ''was'' present in the original releases, but removed when emulating the [=ROMs=] with MVSPSP.[[/note]]

** Similarly, the first boss of ''Metal Slug Advance'' for the UsefulNotes/GameBoyAdvance is Formor, a roughly twice-as-large version of the Metal Slug.

* {{Acrofatic}}: Your character can [[BalloonBody gain some serious weight]] by eating too much health powerups. Other then slowing them down a bit it doesn't deter their agility a single bit.

* JustTrainWrong: The entirety of [[LocomotiveLevel Mission 3]] of Metal Slug 2/X. The rhytm of the "cluckety-clunk" sound remains the same throughout the entire level regardless of whether the cars have bogeys or single wheel sets.

* CompilationRerelease: ''Metal Slug Anthology'' on UsefulNotes/PlayStation2, [[UsefulNotes/PlayStationPortable PSP]], and UsefulNotes/{{Wii}} collects the first seven games in the series (first game through ''6'' and ''X''), though it misses the two UsefulNotes/NeoGeo Pocket games, as well as ''Metal Slug Advance'' and ''Metal Slug 3D'', and the games suffer from slowdown.[[note]]which ''was'' present in the original releases, but removed when emulating the [=ROMs=] with MVSPSP.[[/note]]

* RatedMForManly: The series has StuffBlowingUp, LargeHam, AnnouncerChatter, SugarWiki/AwesomeMusic, MoreDakka, ''VideoGame/{{Contra}}''-level of NintendoHard, [[VideoGame/IkariWarriors Ralf, Clark, and Leona]] from ''VideoGame/TheKingOfFighters'' being included in future entries. This series will surely make your UsefulNotes/NeoGeo grow some balls and chest hair as well as a beard and will make you a man.

* ObviousBeta:
** ''Metal Slug 5''. A lot of the things in the game were cut, and most of it was What Could Have Been. For example, we have no reason as to why the Ptolemaic Army are our enemies, or why the [[GiantSpaceFleaFromNowhere Avatar of Evil]] is the FinalBoss of the game.
** ''Metal Slug 4'' has multiple misplaced music tracks. Early versions of the game had the Final Boss' intro theme switched with his battle theme. The game's OST also had five tracks that are mislabeled and played out of order; the track labeled "Snowy Road" is the most blatant error, as it was clearly meant for Stage 3 yet plays the 1st Boss theme instead. Oddities like Nadia gaining fewer points while using her melee attack than the other characters and the player-controlled Bradley Tank having no MercyInvincibility also point to a rushed development.

* ImplacableMan: Allen O'Neil, Morden's bodyguard who soaks more damage than most tanks, and manages to [[BackFromTheDead come back from the dead]] an unnerving amount of times. In ''Metal Slug 2'', he actually gets eaten by a killer whale which even spits out his bones afterward..?and yet, in ''Metal Slug 3'' he's there again, [[GatlingGood gatling]] and idiotic taunts and all, and he amazes us ''even more'' by [[spoiler:[[BackFromTheDead coming back from the dead]] ''again'' and helping you]] in the endgame. Although he took a vacation after ''3'', not appearing for a few games (the one in ''Metal Slug 4'' [[spoiler:is actually a robot]]), he returns in ''Metal Slug 7''.

** The Ptolemaic Army from ''Metal Slug 5'' stole the blueprints of the titular tanks which allowed them to create their own bastardized Metal Slugs. In fact, the first boss is a titanic Metal Slug dubbed [[Franchise/MetalGear Metal Rear]]. According to ''VideoGame/MetalSlugDefense'', they also seemed to have stolen blueprints of the Rebel Army's vehicles.