History VideoGame / MetalSlugDefense

* LostForever:
** Event units, who are available to purchase within a certain version.
** In ''Attack'', units and special item parts that are received through the Extra Ops and Pack-Shop become unavailable once the event is over, although starting around November, some Pack-Shop units replaced a majority of other units in the Medal Crank.

''Metal Slug Defense'' is a mobile game released rather suddenly by SNK in 2014. As made apparent by the title, it is a TowerDefense game set on the ''VideoGame/MetalSlug'' universe. Players spend a constantly filling meter on characters of varying properties, which then march foward in hopes of overwhelming and destroying the opposite base. The various human, machine and monster units have unique charged moves which sometimes require good timing to be used correctly.

A sequel by the name of ''Metal Slug Attack'', has since been released on Feb. 2016, which vastly improves over MSD in certain aspects, and currently sees constant updates.

* TheComputerIsACheatingBastard: For some reason, the CPU doesn't use special moves until World 3 but it does work [[MyRulesAreNotYourRules by its own rules]] in regards to unit creation. It spawns powerful high-cost units from out of nowhere once you get close or hit its base.

** Instead of dying like other pilots, when the Protogunner is destroyed, Ralf dismounts it and continues the fight on foot. He's just that tough. Attack however swaps him with Tarma with the notion of avoiding a free Ralf. This trait is instead given to Dragunov.

** Gunnner Units have a powerful punch as their standard attack. The Claw Units use a one-two claw punch at close range.

** A trend by the end of the first year of ''Attack's'' release, units of the Extra-Ops are new recolors of either previous bosses or enemies.

* SecondQuest:

* SeeYouInHell: Said by Allen upon dying yet again.

In general, however, it is a well-thought and interesting adaptation.

* {{Cap}}: The level cap for units and the player base's attributes is normally 10, but it expands to 20 once the second world is unlocked, and then the base upgrades cap at 30 once the third world is unlocked. The unit level cap, on the other hand, can only be upgraded to 25 by using Silver Medals. Later updates increased the level cap for units further and the posibility to use MSP to increase said cap up to 35. During gameplay, AP recharge speed can be improved 10 times and there is also a limit to how many units can be sent at once.
* CatGirl: Cat/Lovely Mummies. The Pharao has a couple of them attending him on his War-Dias.
** Lina goes as one for Halloween.

* GoingThroughTheMotions: Characters don't have unique sprites for the cutscenes, only using their idle and attacking animations.

* GuestFighter: The collaboration event brings the titular cats from The Battle Cats into the game. Explained as an accident where Morden attempts to summon the Kraken from Metal Slug 7 via his time travel portal and brings in the cats instead. Needless to say, the fans were more than displeased.
** ''Defense'' also had the entire cast of ''VideoGame/TheKingOfFighters '94''.

** Druganov (a Ptlomaeic HeroUnit who has a custom Flying Unit equipped with a WaveMotionGun) wears a bikini top and whale-tails her underwear out of her fatigues.
** The ''Eternal Summer'' versions of Eri and Fio have them in bikinis.
** Cat and Lovely mummies also wear bikinis

* SoLastSeason: Happens often especially when new and very powerful units come out, being able to counter or eclipse other units' performance. ''Attack'' balances this somewhat, with early units gaining new skills to buff out themselves or their teammates.

* PromotedToPlayable: Almost everything, from the regular mook to those BadAss bosses although some units like the Big Shiee will stay as a boss and will not be playable until several updates later. In ''Attack'' some units from ''Defense'' like the Subway unit that were never playable becomes playable and becomes present in online game play.

* PromotedToPlayable: Almost everything, from the regular mook to those BadAss bosses although some units like the Big Shiee will stay as a boss and will not be playable until several updates later. In ''Attack'' some units from ''Defense'' like the Subway unit that were never playable becomes playable and becomes present in online game play. Interestingly, [[spoiler: it's indicated that an edited Tani Oh will become playable via [[http://imgur.com/Y0WnCZb extra ops]] in December]].

* LostForever: Event units, who are available to purchase within a certain version. In ''Attack'', units and special item parts that are received through the Extra Ops and Pack-Shop become unavailable once the event is over, although starting around October, Pack-Shop units will sometimes appear through the Event Crank.

* NoPlotNoProblem: The intro to ''Metal Slug Attack'' showcases various characters and units running on a desert field with explosions everywhere until a close-up of Morden appears, [[spoiler:even though he is not the final boss of the main game]]. The Extra Ops averts this by giving out explanations to why the event is occurring.

* OhCrap: If a Miner gets hit before setting a barrier or stationary unit, he freaks out and flees. Rumi is also shown panicking in her icon if a mission is lost.

** Issenmantaro serves as this for Hyakutaro, but more focused on close-quarters combat. The Elite Arabian Soldier serves as this for Abul Abbas, with his special attack changed to a charging strike. The Jupiter King MKII serves this as well for the original with its laser attack being replaced to [[MacrossMissileMassacre missile]].

** The Amadeus Corporal in ''Attack'' who wields a machine gun as his normal and special attack who also wears purple uniforms is this to the Soldier units.

** By unlocking their skill in ''Attack'', certain units are able to buff others' HP, attack, or driving if they are both on the same faction (e.g. Marco buffing only P.F. units). Putting certain units in a deck will also let those gain more HP or use less AP to put on the field (e.g. Leona, Ralf, and Clark will gain 10% more HP for themselves if they are together in a deck).

* TookALevelInBadass: A majority of units in ''Attack'' have been buffed up and are able to handle any new and upcoming units. Jupiter King, for example, can now use his missiles alongside the laser.

** Morden's special is to summon the Hi-Do to drop bombs everywhere. The Hi-Do cannot be damaged at all, and it will drop at least one bomb on the enemy base, making it guaranteed to do damage.

** Instead of dying like other pilots, when the Protogunner is destroyed, Ralf dismounts it and continues the fight on foot. He's just that tough.

** Hunter Walker is normally a grounded unit, but its special ability allows it to CeilingCling and start dropping eyeball bombs in a manner similar to General Morden's Hi-Do special, though the bomb can be blocked from hitting the base if it hits a large unit.

** It is heavily implied to be this ''Attack'', as well as requiring 2600 medals for a 10 medal mystery crank in hopes to get a better unit just to win. Pre-acquisition units can also be this, but instead of paying for it with medals, a player must pay ''$100'' for 100 parts for that particular unit as well as an exclusive gold bordered avatar that come with it. Thankfully, these pre-acquisition units will eventually become obtainable via medal crank, so if you want a powerful pre-acquisition by spending medals instead of cash, you just have to wait.

* TheGoomba: The basic blue soldier you start with. Cheap and with 400 HP at level 20. He attacks at close range with a knife and can throw granades. The green normal rebel soldier is an unlockable and he has even less health (360 at level 20) for an even lower price.

* In the Missions, you get to fight Big Shiee (the boss from Metal Slug 2[=/=]X, Mission 3).

** The Huge Hermit - who is the only enemy on its mission - even instakills anything it hits, no matter how much health the target has... ''except'' the [[https://www.youtube.com/watch?v=EWffjEYmd0Q Stone Turtle]], which can even block it.

** It is heavily implied to be this ''Attack'', as well as requiring 2600 medals for a 10 medal mystery crank in hopes to get a better unit just to win. Pre-acquisition units can also be this, but instead of paying for it with medals, a player must play ''$100'' for 100 parts for that particular unit as well as an exclusive gold bordered avatar that come with it. Thankfully, these pre-acquisition units will eventually become obtainable via medal crank, so if you want a powerful pre-acquisition by spending medals instead of cash, you just have to wait.

** The new unit from the Destroy The Tower extra ops in "Attack" is the Amadeus Corporal who deals thousands of damage as well as having about 10,000 HP.

** The Amadeus Corporal in "Attack" who wields a machine gun as his normal and special attack who also wears purple uniforms is this to the Soldier units.

* TheCameo: Every heroic character from the series is at least mentioned in the game, even those from the ''Mission'' and ''Advance'' spin-offs, the Ikari Warriors (including Whip and Heidern), and even [[NoExportForYou the other mobile spin-off titles.]] The villain side doesn't get such attention, though recent updates have been trying to rectify that with new units and extra missions.

* LimitBreak: A [[ActionBomb self-destructing SV 001]] can be sent when its meter fills. It insta-kills a good number of small enemies before exploding upon colliding with a larger enemy or the opposing base. This is important when fighting Jupiter King, which [[InstantDeathRadius makes such a mess]] out of anything you send at it that, at least early on, you're forced to just buy time and try to get rid of large enemies until the bombastic SV 001 is available for damaging and pushing King away.

* PaletteSwap: Issenmantaro serves as this for Hyakutaro, but more focused on close-quarters combat. The Elite Arabian Soldier serves as this for Abul Abbas, with his special attack changed to a charging strike. The Jupiter King MKII serves this as well for the original with its laser attack being replaced to [[MacrossMissileMassacre missile]].

* Rescuing [=POWs=] in ''Attack'' has been made easier due to them always appearing in the same spot in a level. Instead of boosting AP production, base HP, etc., they instead gave out a random item out of a stage's list.

* TeamSpirit: If a deck is filled by a single faction, they all gain a 10% HP bonus. By unlocking their skill in ''Attack'', certain units are able to buff other's HP, attack, or driving if they are both on the same faction (e.g. Marco buffing only P.F. units). Putting certain units in a deck will also let those gain more HP or use less AP to put on the field (e.g. Leona, Ralf, and Clark will gain 10% more HP for themselves if they are together in a deck).

* [[spoiler: AWinnerIsYou: The game reuses the ending scene form ''Metal Slug 3'', while talking about how the heroes will continue to battle any evildoers. The same ending plays on all three loops.]]

* AttackAttackAttack: All units will advance foward and exchange fire with enemies until being killed.

* DeathFromAbove: The Parachute Truck. It fires a bunch of bombs into the air that rain down and pierce enemies until they hit the ground.

* MegatonPunch: Ralf has the notorious Galactica Phantom punch as his special attack.

* OriginalGeneration: Starting with the Mummy's Event in ''Attack'', some events would include units never seen in other games such as Pharaoh's Arc (the mummy's leader) and Dragunov (a Ptolemaic commander).

A sequel by the name of ''Metal Slug Attack'', has since been released on Feb. 2016, which vastly improves over MSD in certain aspects. (Which currently sees constant updates.)

* OhCrap: If a sandbag man gets hit before setting a barrier, he freaks out and flees. Rumi is also shown panicking in her icon if a mission is lost.

* SkillGateCharacter: Leona. She costs 80 AP, can destroy early units and bases with ease with her powerful melee attacks and special, and is very hard to handle with a beginner's deck. She falls against more experienced decks due to being melee-only- once Claw Robot and Utan are out, she becomes easy to take care of. [[GameBreaker Until the sequel, that is].
* SoLastSeason: Happens often especially when new and very powerful units come out, being able to counter or eclipse other units' performance.

** The fight against Tetsuyuki has this sense of urgengy, due to the boss being able to use a laser that hits the entire field.

* SequentialBoss: Crablops. When its initial health reaches zero, its bottom will be destroyed, but its top will fly off and turn into another high-health unit, similar to being the second and third boss of ''Metal Slug 7''.

* SkillGateCharacter: Leona. She costs 80 AP, can destroy early units and bases with ease with her powerful melee attacks and special, and is very hard to handle with a beginner's deck. She falls against more experienced decks due to being melee-only- once Claw Robot and Utan are out, she becomes easy to take care of.

** Morden may have a great special attack, but his standard attack is not as effective as his 950 AP cost would lead you to believe and he tends to get knocked back often, leaving the rest of your units exposed as he tries to make his way back to the front.