History YMMV / MetalSlugAttack

* EvilIsSexy: A majority of the new female villains, especially the Ptolemaic crew.

* TierInducedScrappy:
** Jupiter King MK II is often referred as the the worst and most unnecessary pre-aquisistion unit. MK II's original intention in ''Defense'' was to be a foil to the original Jupiter King, as the latter only used its laser and the former used only its large missiles. In ''Attack'', Jupiter King was upgraded to use its missiles alongside the laser, making MK II obsolete. It's status was further cemented with the release of its mini version, which was far cheaper and had far better stats.
** The Box and Step Up Crank units get notoriety for being overly powerful. It doesn't help that they can be only accessed by using their respective crank, unlike the pre-acquisitions who eventually drop to the Medal Crank and Shops.
** Beatriz (and her variants) is infamous for her powerful ice laser that has an extremely long range. Worse, any defeated units are turned into hefty ice blocks. She is known for being useful since her introduction (where now most newer units outclass her, at least until she got a Subjugation Tactics form) as long there is protection surrounding her.
** Recent United Front units have gotten a lot of flak for being very underpowered compared to the first UF units, but nothing compares to the Golden Gunner and Golden Metal Rear EX. The Golden Slugnoid does everything the Gunner does but better, and the Metal Rear's attacks are absolutely pathetic for its extreme cost. [[labelnote:For Example]] the Mirage Pirate released beforehand had significantly higher DPS for around 90 AP; Metal Rear costs around ''500 AP''[[/labelnote]] Rubbing more salt into the wound, both units were beloved by the fanbase for their design despite being left obsolete for years, and they ''still'' can't be used in the meta.
** On the high end of things, Special Amber is an extremely popular pick across all ranks, even more so than the original Amber. Special Amber is a very good tank for her cheap cost, because she can close the distance easily with her very dangerous piercing attacks.
** Ptolemaic Decks are hard to form since most of the essential units are hard to maintain or unavailable at the time of writing this, but are absolutely monstrous. The Ptolemaics already have obnoxious (Quadro Jumper, Josette, Lucy, Wall Drone, Rebel Caroline, Phoebe) and somewhat okay units (Golden Hound and Golden Gunner Unit), but with buffers and the full fraction hp bonus, they are simply insurmountable. Also, the Ptolemaic fraction has by far the most base pokers out of all the other armies.

* AuthorsSavingThrow:
** Around every two weeks, the game gives out quality-of-life updates. Some updates even go as far as allowing old units to be obtainable again.
** After the first Snatch Wars Guild Ops, the later ones reduced the number of sorties for an attack and the health of the attacking units. This allows the guild to get the unit without running out of sorties quickly.
** Try Line Ops, the replacement to Snatch Wars. Not only does it allow guild members to actually collect the unit without competition and earn respectable rewards but also introduces new boss units to combat the various recolors.
** Task Force Ops is basically Free-To-Play galore. If one can play their units right, they can amass a boat load of crank keys that can earn the player most of the older Extra Ops units. A player with many platinum frame units can trade the surplus of respective unit parts to earn more Mars Coins than ever. This is intentional as SNK updated the Mars Shop, so the player can purchase previous Snatch Wars, United Front, and Try Line units.
** The introduction of Status Strengthening Items effectively made old units useful again as these put their stats on par with newer units.
** The 5th anniversary update altered a large amount of units for the better. This includes lowering their invincibility, removing fake walls from their attacks, having to spawn a few meters away from the enemy base, and stunning only working for the first instance per enemy unit. This vastly mitigates the strong early-game meta and allows matches to last longer and be more entertaining.

*** [[FanNickname OMAR]] (One-Man Army Ralf). His flamethrower has pierce and ridiculous range (And since it counts as an incendiary attack, Ralf can easily deal with units that are weak to fire, which is ''a lot''), Get him anywhere near your base and its good as over. Try to knock him back he becomes invincible and sprays his flamethrower and that is only his first form. He is an absolute monster in his second form. almost impossible to stop thanks to having stun and knock back immunity. his Vulcan punch deals out massive damage in quick succession while his Counter galactica deals out thousands of damage while giving him invincibility. His God phoenix dynamite will wreck the AP's out of your boss units. Not even Maria can stop his rampage and she herself is quite monstrous, with Geweih Metzelei being one of the few who can stand up to him in a straight-up fight.

*** [[FanNickname OMAR]] (One-Man Army Ralf). His flamethrower has pierce and ridiculous range (And since it counts as an incendiary attack, Ralf can easily deal with units that are weak to fire, which is ''a lot''), Get him anywhere near your base and its good as over. Try to knock him back he becomes invincible and sprays his flamethrower and that is only his first form. He is an absolute monster in his second form. almost impossible to stop thanks to having stun and knock back immunity. his Vulcan punch deals out massive damage in quick succession while his Counter galactica deals out thousands of damage while giving him invincibility. His God phoenix dynamite will wreck the AP's out of your boss units. Not even Maria can stop his rampage and she herself is quite monstrous.

* TheWoobie: Vita. First she loses her original companions, gets severely injured and is unwittingly turned into a poorly-made cyborg, shuts off her personality in fear of losing her new friends, and tends to have suicidal rampages when fighting. Some time in the future, Vita gets shoved in a test tube with her limbs removed while robotic clones of her are created for battle.

** Somebody outdid themselves with the [[LethalJokeCharacter Reacher]], and they should be punished for it. Incredibly cheap(even the base Bronze frame is less than 100 AP), fast as hell, does obscene damage, and heals itself while attacking. It can tear through nearly every unit that can be brought out as fast as it, and will typically follow right through to destroy you base in seconds. The only unit that can reliably stop it is another Reacher.

* FoeYay: Abigail and Trevor. Surprisingly, there is no known vitriol with Trevor and Nadia fans.

** Yute [[note]]Caroline became a large EnsembleDarkhorse in the Spanish-speaking community due to her design and her shout of "[[{{Mondegreen}} Yute]]" when attacking. Yute is also her FanNickname[[/note]]

* CreatorWorship: Towards Dai-Addict, the first known animator and character designer of the game (e.g. Abigail, Nova, and Rita), mostly for her drawings of the game's characters on Twitter and Pixiv. People were concerned about her sudden disappearance, but there was relief when a new concept art revealed she was still working for SNK [[note]]Her lack of activity was due to reports of stalking, not copyright[[/note]].

* FanonDiscontinuity: Considering ''Attack'' (alongside ''Metal Slug Defense'') was prioritized for many years prior to the announcement of a new mainline entry in 2019 (a decade since ''Metal Slug XX''), a good section of fans ignore anything related to this game. And [[PlayTheGameSkipTheStory most of these skip the story cutscenes anyway]].

** Before resorting into using text box cutscenes, a good portion of early Extra Ops (which were sprite animated) were criticized for not having a plot.

* BaseBreakingCharacter: The new characters, although [[EnsembleDarkhorse some players have their preferences]]. Part of stems on how some of them do not fit the game's aesthetic (or their respective Army affiliation), the overly fanservicey designs of some of the characters, and/or the power they have compared to a massive tank.

* FanonDiscontinuity: Considering ''Attack'' (alongside ''Metal Slug Defense'') was prioritized for many years prior to the announcement of a new mainline entry in 2019 (a decade since ''Metal Slug XX''), a good section of fans ignore anything related to this game.

** $NK/Snek [[note]]Although this applies to ''Defense'' as well, the former name is used for the game's very blatant uses of making people fork up cash for [[SNKBoss powerful units]] [[PowerCreep that sooner or later lose their effectiveness]]. The latter name is a literal pronunciation of SNK, and both are sometimes combined to make "$NEK". The "$NK Boss" is also a combination of this and the SNKBoss trope. Before the company's name change, $NK Paymore ([=SNK=] Playmore) was also used.[[/note]]

** $NK/Snek [[note]]Although this applies to ''Defense'' as well, the former name is used for the game's very blatant uses of making people fork up cash for [[PowerCreep powerful units that sooner or later lose their effectiveness]]. The latter name is a literal pronunciation of SNK, and both are sometimes combined to make "$NEK". Before the company's name change, $NK Paymore ([=SNK=] Playmore) was also used.[[/note]]

* The latest hated units are the Mirage Pirate and Flying Parasite (Type E), Both are relatively powerful, Low AP units that wreck most Early-Game units, including the recent anti-rush units(plus the Parasite has a Stunning melee attack for good measure, so it can often kill units that would otherwise be strong counters for it). And both have charging dodges that put them in optimal killing range for anything that manages to come out and challenge them.

* SugarWiki/AwesomeArt: Most of the new units still continue to sport the same fluid animations as in the main series. The Fortmeranian and Iwa Oh have recently gotten alot love, since they wouldn't look out of place in the mainline games.

* FanonDiscontinuity: Considering ''Attack'' (alongside ''Defense'') was prioritized for many years prior to the announcement of a new mainline entry in 2019 (a decade since ''Metal Slug XX''), a good section of fans ignore anything related to this game.

*** ''Doctor'''. At the time, his special was one of the most damaging in the game. What really made him dangerous was that he could call as many blimps as he wants, which can deal an absolutely insane amount of damage. The attack can also reach annoying backlines like the Incredibly Trio, basically causing an end to the the meta. Untill he got needed to spawn only one blimp at a time, but being one of the few units ''ever'' to get nerfed really cements this status.

** The release of the Elder Centipede nearly snapped the meta in half. It digs like Zoni, so it can't be smiled by long ranged units. Not that it matters, since its hp is at 900k and it can only be hit in the head, which a surprising amount of crank units can't do well. The main thing that makes the Centipede so deadly is its special attack, the damage if every single attack hits is ''disgusting'' and has IVs through the entire attack, and chews up previous deadly units like Growl and Josette like they are creeped units. Banden also released a video of the thing ''demolishing Jephet and Harriot'' with ease, who are crank units that require much more resources to get. The only thing holding it back is its extreme ap cost and the long delay inbetween digs. The Elder Centipede is the next Doctor, a free unit that can destroy most of the gacha units easily.

** The Extra Ops tends to get flak for reusing the same five types with little to no variations.

** Before resorting into using text box cutscenes, a good portion of previous Extra Ops (which were sprite animated) were criticized for not having a plot.

** Metal Slug 8. [[note]]After [=SNK=] returned to the home console scene in 2016 with ''King of Fighters XIV'', fans were eager for a new entry of the main series after being dormant for almost a decade. It took until 2019 for a new entry to be announced in development, and there's debates on whether the ''Attack'' characters will make any sort of appearance.
[[/note]]
** Big Shieet [[note]] The Big Shiee variant released during Beserk's event gotten alot of flak for being a very garbage unit, while previous Shiees have been extremely useful units or just average. The Mirage Shiee's special attack hardly deals any damage compared to the likes of other Shiees, and its normal attack can hardly do its job because the unit keeps spamming its evasion ability. [[\note]]

** ''Snatch. Wars''. By far, the most despised EO in the game, and for good reason. Guilds would compete with three other Guilds, winning NPC battles to claim or steal territory. The amount of territory held determines how much rewards, and most importantly, parts of the featured unit the Guild gets. The problem was that Snatch Wars had awful matchmaking; you could be paired up with three whales who had thousands of Sorties to spare who would swallow up the map, denying you and your guild ''almost any rewards''. Or you could be paired up with outright ''hackers'', which was the case in Japan. The amount of cheating was so bad in the event for the Sister Nokana (which was a pretty underwhelming unit on its own) that SNK flat out handed the unit for free.

** Task Force is very luck dependent compared to other Extra Ops. You could either get two Diamonds, which greatly increases rewards, or have your entire team crippled with ''permanent seals, losing 9/10 max hp, or outright leaving your deck.'' While the featured units are well worth pain, it can still feel annoying when 99% percent of your deck is unusable. And the Hell Stages are some of the most unforgiving yet, the first Task Force first regular battle literally baselocks you in the first seconds.

** Beatriz (and her variants) is infamous for her powerful ice laser that has an extremely long range. Worse, any defeated units are turned into hefty ice blocks. She is known for being useful since her introduction (where now most newer units outclass her, at least untill she got a Subjugation Tactics form) as long there is protection surrounding her.
** Recent United Front units have gotten a lot of flak for being very underpowered compared to the first UF units, but nothing compares to the Golden Gunner and Golden Metal Rear EX. The Golden Slugnoid does everything the Gunner does but better, and the Metal Rear's attacks are absolutely pathetic for its extreme cost. (For example, the Mirage Pirate released beforehand had significantly higher DPS for around 90 AP; Metal Rear costs around ''500 AP'') Rubbing more salt into the wound, both units were beloved by the fanbase for their design despite being left obsolete for years, and now they ''still'' can't be used in the meta.

** Ptolemaic Decks are hard to form since most of the essential units are hard to maintain or unavailable at the time of writing this, but are absolutely monsterous. The Ptolemaics already have obnoxious (Quadro Jumper, Josette, Lucy, Wall Drone, Rebel Caroline, Pheobe) and somewhat okay units (Golden Hound and Golden Gunner Unit), but with buffers and the full fraction hp bonus, they are simply insurmountable. Also, the Ptolemaic fraction has by far the most base pokers out of all the other armies.
* WhatCouldHaveBeen: Comes home to roost. Some of the cut units from the arcade ''Metal Slug'' games are reused here, such as the Stone Turtle and Ptolomaos.

** The release of the Elder Centipede nearly snapped the meta in half. It digs like Zoni, so it can't be smiled by long ranged units. Not that it matters, since its hp is at 900k and it can only be hit in the head, which a surprising amount of crank units can't do well. The main thing that makes the Centipede so deadly is its special attack, the damage if every single attack hits is ''disgusting'', and chews up previous deadly units like Growl and Josette like they are creeped units. Banden also released a video of the thing ''demolishing Jephet and Harriot'' with ease, who are crank units that require much more resources to get. The only thing holding it back is its extreme ap cost and the long delay inbetween digs. The Elder Centipede is the next Doctor, a free unit that can destroy most of the gacha units easily.

** Beatriz (and her variants) is infamous for her powerful ice laser that has an extremely long range. Worse, any defeated units are turned into hefty ice blocks. She is known for being useful since her introduction (where now most newer units outclass her) as long there is protection surrounding her.