History VideoGame / TwentyXX

* PlatformHell: Level 9 is a MarathonLevel with some of the most difficult platforming challenges in the game. It combines [[FloatingPlatforms all of]] [[TemporaryPlatform the previous stages']] [[SpikesOfDoom platforming elements]] with impunity, spices it up with [[LaserHallway Boltpairs]], [[BoobyTrap Ice Architects]], and [[{{Fireballs}} Flamespewers]] en masse, and populates them all with numerous enemies ready to block your progress and knock you into pits. On top of ''that'', probably a good 80% of the level is made up of said platforming elements, which means that when you ''do'' fall into a [[NonLethalBottomlessPit bottomless pit]], the spot [[BottomlessPitRescueService you get ported back to]] — that is, the last bit of solid, safe ground you touched — is likely to be [[CheckpointStarvation a considerable distance back.]]

''20XX'' exited Early Access on August 16th, 2017 for PC. It was later ported to UsefulNotes/PlayStation4, UsefulNotes/XBoxOne, and UsefulNotes/NintendoSwitch on July 2018.

* JokeCharacter: [[spoiler:Vika and Jest. Prototypes, but functional, versions of Nina and Ace]] unlocked by finishing the game on Defiant with at least 3 skulls. They have half of the normal starting health, only 2 weapon energy, their weapons deal halved damage, and items on shop have their cost ''doubled''. Oh, and they cannot find new basic weapons nor Cores. The only, erm, positive trait about them is that prototype augments will have their positive benefits doubled; they can potentially become [[LethalJokeCharacter Lethal Joke Characters]] because of that.

* LoadBearingBoss: [[spoiler:Killing Dr. Arlan Flat causes the entire facility to self-destruct. [[JustifiedTrope Justified]] since he's specifically said to have installed a dead man switch in his heart to test his creations one last time should one finally kill him.]]

** Some of the Augs allude to their introduction to their first appearance in a build, like how the Meganut [[AscendedGlitch could initially be purchased in shops]] or that the Spillover Matrix used to also convert energy to health before being [[{{Nerf}} nerfed]].

*** It makes you run faster and its description says [[Anime/{{SonicX}} "Gotta go fast"]].

** The Heart Container works almost exactly as it does in ''VideoGame/TheLegendOfZelda'' series, minus the full health restore. The description for the Striking Feather also references chickens that attack in swarms when provoked.

** There's a Challenge Skull named "Final Destination". The menu icon is a silhouette of [[VideoGame/StarFox Fox]]'s head with a mockup of ''[[VideoGame/SuperSmashBros Melee's]]'' [[VideoGame/SuperSmashBros Final Destination inside it]]. The flavor text for the skull is [[MemeticMutation "No items. Fox only," and ultimately references the other widespread use of the term 20XX]].

* VideogameCaringPotential: [[spoiler:Al has been caged up during the EscapeSequence, and you can choose to free him by breaking the cage, or [[VideoGameCrueltyPotential leave him trapped inside the exploding space station]].]]

* CloningBlues: [[spoiler:The final boss fight reveals something that's been hinted at since beta: Nina and Ace have been destroyed and recreated over and over again by Dr. Sharp and Dr. Flat for testing. The final two levels see Nina and Ace turning against their creators to break the cycle of death and rebirth.]]

* GameplayAndStoryIntegration: The FlavorText for the [[EverythingsBetterWithPenguins Peng enemy]] mentions that Dr. Flat received his own personal toy-sized model after the Board acquired the rights to it. [[spoiler:Sure enough, during the final EscapeSequence, you can find said model in what is presumably his room.]]

* EverythingsBetterWithPenguins: Shatterbeak, the mooks he is based off of, and the Repro based off of those are all penguin robots.

* EverythingsBetterWithSpinning: Especially with Ace's cool Spinning Glaive.

* SelfImposedChallenge: Challenge Skulls, which can be activated in Defiant/Hardcore mode. Effects range from longer stages, higher enemy density, running the game 50% faster, dying instantly to hazards, and doubling damage taken from enemies.

* AlwaysAccurateAttack: [[spoiler:Subverted and inverted. Dr. Flat's mech switching sides causes an explosion that sends your character into a damage animation... Except apart from knockback, it does not actually decrease health and in fact invokes MercyInvincibility from the normal contact damage from the moving mech.]]
* AnAdventurerIsYou: The Core Augments - armor parts - can, and might, change the playstyle wildly depending which one you go for:

** '''The DPS 2:''' ''Owlhawk, the Wise''. The set focuses on special weapons and having all of them allows any character to cause a lot of damage while having tools for any situation. However this style is limited by the amount of weapon energy the character has.

** A run can last very long, normally about half an hour. At the end of each level you have the option to save your game and continue later.

** Upon using the small circular teleporters (commonly found in Frostor) you have a small period of invincibility. This prevents an enemy camping on it to get a cheap shot on the player and also prevents stages hazards from catching them off-guard as well.
** Playing on Reverent or Normal on co-op allows one player to teleport to another by holding the "pick up augment" button. This might be helpful to lead one player to a chest or to help someone cross a troublesome section of a level safely. However this is disabled on Defiant difficulty.
** Falling platforms on co-op will take longer to start falling than in solo matches to prevent players from accidentally sabotaging each other.
** Death Lotus's bossfight, which revolves around him disappearing into the wall after making a few attacks and emerging from a randomised point, was tweaked so that a red marker would appear around the point he would emerge from. This allows Ace, who has no non-power ranged attacks, to close in on his location and start whuppin' rather than having to rush there in the hope of getting in a couple of swings before he bails.

* ArmorAsHitpoints: You can collect it periodically through various means, and it will act as a 1:1 shield protecting your hitpoints. While you have at least one point of armor active, you are also ImmuneToFlinching.

* AsteroidsMonster: If he's not fought as the first boss, once killed for the first time Rollster Beta will cause him to divide into two, smaller Rollsters with less health, and can divide a second time if fought late enough. The miniature hamster wheels based off of him also share this property, though they divide into only one of their weaker versions.
* AstralFinale: The final level [[spoiler:both of them]] takes place on The Station, with the Earth as a backdrop.

* AuthorityEqualsAsskicking: [[spoiler:Dr. Arlan Flat, chief of the project and FinalBoss, he's quite tough as well]].
* AwesomeButImpractical: The prototype augments often give you massive bonuses but not with an equally heavy penalty and you can get more than one. Some of the characters can work around the handicaps, but woe is the unaware soul who picks the wrong prototype at the wrong time. To give some examples.
** Hawk's World Igniter has bar none the highest [=DPS=] of the entire game. The catch? It is ''extremely'' energy consuming and even with Owlhawk's Focus (which reduces special ammo consumption in 50%) it will eat through your energy gauge before you can finish saying ''[=Twenty-Double-X=]''.
* BadBoss: Drs. Sharp and Flat take ''entirely'' too much pleasure in the deathtraps they put Ace and Nina through, will happily insult them for the smallest perceived slight, [[ThrownOutTheAirlock space them]] or [[StuffBlowingUp detonate their bodies]] if they fail a run, and [[spoiler:they'll both take their turns fighting you to the death should you make it far enough.]]
* BagOfHolding: There's no real limit to how many augments you can hold. You can carry all 8 powers as well[[note]]Unless your character has exclusive powers, in which case they will compete for the eight spaces for powers.[[/note]], but have only 3 of them active at a time.

** N-Buster for Nina and A-Saber for Ace are not the most exciting weapons of the game but are generally well-suited for most situations. Likewise Hawk's whip, the Siphon, is not terrible to the point of being considered an EmergencyWeapon, but is by far and away her most "boring" weapon.

* BossCorridor: Before every boss in true Mega Man fashion. You'll often find some goodies inside that may or may not help you.
* BossDissonance: Due to how levels are formed and depending on which boss you're more used to fight you can have EasyLevelsHardBosses and HardLevelsEasyBosses in the same run.

** [[spoiler:Dr. Brighton Sharp, Duke of Development]]
** [[spoiler:Dr. Arlan Flat, Chief Out of Control]]
* BottomlessPits: Most of the generated levels float over one, with the exception being the Factory levels which are completely closed in. Falling into one will subtract a health point before teleporting you back to the last safe ground you were touching.

* BreakingTheFourthWall: [[spoiler: The very first thing Dr. Arlan Flat does during his boss fight is destroy his own health meter, preventing you from seeing how much health he has at a glance (Flat's mech has a health bar of lights underneath his cockpit).]]

* ChangingGameplayPriorities: Happens more often than not, at the start of one level you can have moderate Attack, at the end you might have a lot more Power and Owlhawk armor parts and change considerably your playstyle.

** The Dracopent set revolves around charged attacks - the head will store two charged attacks at once, the arms will allow for a third-level charge, and the SetBonus causes all attacks to come out as a second level charge though they can still be charged for the third one.

* CloningBlues: [[spoiler: The final boss fight reveals something that's been hinted at since beta: Nina and Ace have been destroyed and recreated over and over again by Dr. Sharp and Dr. Flat for testing. The final two levels see Nina and Ace turning against their creators to break the cycle of death and rebirth.]]
* CloseRangeCombatant

* ColossusClimb: Sort of. [[spoiler:The FinalBoss must be hit in the cockpit of his HumongousMecha, so Ace or Nina must climb a series of precarious platforms in order to be able to damage it]].

* ContextSensitiveButton: The same button used to pick up augments and weapons is also used to use vending machines... Or pet Dally in the [=HQ=].

* CriticalStatusBuff: Crisis Overdrive increases all status if Nina or Ace's health drop to red. Crisis Timestopper freezes all enemies for 3 seconds if they drop their health to red as well. [[spoiler: Inverted with Contractor Beta, which makes you more powerful at full health, but get weaker the less health you have.]]
* DamnYouMuscleMemory: Every foot core augs have different commands - double jump, double jump to hover ''or'' fly or a multi-directional air dash.

** Playing with Draco feels very awkward at the start because you must press Up + Attack in order to use his charge attacks. Considering some of his attacks can propel him upwards or forward it's very easy to mess up an input and throw yourself in harm's way.

* DeathIsCheap: Not for ''you'' it isn't, as it results in you losing everything you've acquired that run. That said, [[spoiler: if Nina or Ace is destroyed, their consciousness can easily be retrieved and placed into a new body.]]

** Hawk in general. She starts out as the weakest of the three characters. Her strengths lie in her near limitless supply of energy to fuel special weapons.

* DiscOneNuke: Finding the Dracopent's Claw (which allows an even more powerful charge) and Dracopent's Fang (next attack also becomes charged) early in the game is rare, but if you happen to bump in any of these (or both) early bosses can be slaughtered in ''seconds'' even without Attack augments, especially when combined with weapons like the Scatterblast with strong charge scaling.

* DontCelebrateJustYet: Once [[spoiler:Dr. Arlan Flat]] is defeated Nina and/or Ace must escape the self-destructing station.
* DroughtLevelOfDoom: Can be invoked via challenge skulls. Famine will make the game never drop health, Bankrupt will make nuts never drop, Final Destination will make all items to vanish.
** The Kingseeker prototype aug gets rid of all health drops for the rest of the run, but you get a complete refill when you kill the boss.

* EarlyGameHell: The beginning of runs, especially in Defiant with challenge skulls, can be very rough until you start finding augments. Especially painful if you're playing as Hawk, who starts with a weak melee attack and an equally weak but long ranged sub weapon.

* EmergencyEnergyTank: Crisis Lifebank repro will collect any health pickups close to you. They automatically self-destruct once your health gets very low releasing some of the health they've collected.
* EquipmentBasedProgression: There are no [=EXP=] or level ups here. You become stronger by finding augments and armor parts.

* EvilKnockoff: [[spoiler:The FinalBoss sends failed, barely functional, copies of Nina and Ace against them. Some are capable of using charged attacks and are actually dangerous, while others just charge mindlessly or simply self-destruct when close enough to the heroes]].
* ExactWords: Very Safe Labs. Well, the lab ''itself'' is safe. It's just that the upgrade in it might be...''troublesome''.

** [[spoiler: Dr. Brighton Sharp, who wears a battlesuit equipped with all of the previous bosses' special weapons, though some of them work a bit differently than yours.]]
** [[spoiler: Dr. Arlan Flat as well, to a lesser extent. He doesn't attack you directly until you've dealt some damage to him, but when he does, he uses the bosses' weapons. You also have to go through some of the hazards of the previous stages just to get to a position to hit him.]]

* FlavorText: All over the datalore. Ranges from silly, random to downright weird.

** [[spoiler: Dr. Arlan Flat summons clones of Nina and Ace to fight you in the intermissions of the fight. They're fragile, but some of their attacks do double damage if they hit you.]]
%% * {{Foreshadowing}}: In the intro Dr. Sharp gets his hair burnt and comically shaped just like Dr. Flat's. [[spoiler:You end up fighting him at the end of Level 9]]. (Not entirely sure why this is foreshadowing.)
* {{Foil}}: Dr. Brighton Sharp to Dr. Arlan Flat. Going beyond the pun of their names... [[spoiler:Sharp fights you directly, wearing a power armor, and using modified versions of the special weapons you can acquire throughout the game. Flat, however, is cowardly and even though he's piloting a gigantic spider mecha he prefers to let his "arena" fight for him attempting to wear down the player by making them running through several trap courses while throwing defective models of Nina and Ace and eventually attacking as well]].
* FragileSpeedster: The Leafmetal Plating augment, reducing damage in favor of runspeed.

** Oxjack's Core Augments provide little in the way of protection beyond a shield that's only active while dashing with the torso upgrade. For contrast, both Owlhawk and Dracopent let you regenerate health by killing enemies with the appropriate methods, and Armatort boosts health pickups by making some of them also grant you armour. However, Oxjack's augs let you use it midair - multiple times, if you have the SetBonus - and allow you to quickly and efficiently charge your weapon.

* GetBackHereBoss: [[spoiler:Dr. Arlan Flat]]. He runs away after taking enough damage or a set time once you damage him.

** [[spoiler: The Hysteria augment ''triples'' damage taken, but doubles the effect of any non-prototype augs you pick up.]]
* GuysSmashGirlsShoot: Ace is a close-quarters combatant while Nina makes use of long ranged weapons. The same goes for Hawk and Draco; while Hawk usually has to get close to use her Siphon to recharge her special weapons she has no real strong melee attack, Draco on the other hand has access to ranged weapons, but, like Ace, his most devastating attacks are usually the melee ones.

* HaveANiceDeath: If (or when) you fail a run you usually get a last dismissive commentary from the game. Additionally [[spoiler:Nina and Ace have special cutscenes where they are blown to bits or flung into space at the end of failed runs.]]

* HelmetsAreHardlyHeroic: A rare villainous example. [[spoiler:Dr. Brighton Sharp doesn't wear anything to conceal or protect his face when fighting Nina or Ace]].

* HumongousMecha: [[spoiler: Dr. Flat pilots a gigantic [[SpiderTank spider mech]].]]
* HyperactiveSprite: Even when standing still all Contractors are always rocking back and forth ready for combat.

* IncreasinglyLethalEnemy: Death Lotus will create other small petal enemies to rain projectiles in his arena. If fought on later levels the boss can create from 2 to 3 at the same time.
* JokeCharacter: [[spoiler:Vika and Jest. Prototypes, but functional, versions of Nina and Ace]] unlocked by finishing the game on Defiant with at least 3 skulls. They have half of the normal starting health, only 2 weapon energy, their weapons deal halved damage, and items on shop have cost ''doubled''. Oh, and they cannot find new basic weapons nor Cores. The only, erm, positive trait about them is that prototype augments will have their positive benefits doubled, they can potentially become [[LethalJokeCharacter Lethal Joke Characters]] because of that.
* JustifiedExtraLives: Dying in a run is ''quite'' final... For that particular body. Then Nina or Ace's "soul" simply gets transplanted into a fresh new body that Sharp and Flat had been working on upgrading.

* LedgeBats: Flapps have a very bad habit of knocking you into pits, lava and the like, but ''any'' enemy in Level 9 has potential of being one.
* LevelInBossClothing: [[spoiler:Dr. Arlan Flat can feel like this as you will probably spend most of the time dealing with the obstacle course in his arena]].

* LoadBearingBoss: [[spoiler: Killing Dr. Arlan Flat causes the entire facility to self-destruct. [[JustifiedTrope Justified]] since he's specifically said to have installed a dead man switch in his heart to test his creations one last time should one finally kill him.]]

* LootCommand: Augments (and Cores and weapons) must be manually picked up. [[Administrivia/TropesAreTools Thank goodness for that]] - some augs will decrease stats, and automatic pickup would result in many runs where you only have two health.

* MarathonBoss: [[spoiler:Dr. Arlan Flat]]. The battle can be VERY long if Nina or Ace are lacking in attack or power augments as the boss will always run to the other side of a very large arena once he's hurt.

* MaximumHPReduction: Some augments and prototypes offer status increase in exchange of [=HP=]. The red vending machine allows you to swap maximum health for money. The Final Shell prototype [[HPToOne drops maximum health to one 1]] exchanging it for armor in 1:2 ratio.
* MercyInvincibility: Every time you get hit, but it usually doesn't last very long and careless players will get hit multiple times. The Mistimed Protector augments increases the duration of post hit invincibility, though.

* MultipleEndings: Kinda. The overall ending is the same, but the final cutscene still is slightly different depending on [[spoiler:whether or not you choose to free Al Bot in the final level.]]

* NewGamePlus: In a sense. The more you play, the more augments you can unlock spending Soul Chips adding more variety to later runs.

* PathOfMostResistance: If an alternate path is generated by the level you can bet you'll have extra platforms, enemies and spikes waiting before you reach that crate or chest. Downplayed with Shops (or Very Safe Laboratories) as while they can have obstacles in the way, they'll always be much tamer than ones leading to extra loot.

* PlatformHell: Level 9 is a MarathonLevel with some of the most difficult platforming challenges in the game. It combines [[FloatingPlatforms all of]] [[TemporaryPlatform the previous stages']] [[SpikesOfDoom platforming elements]] with impunity, spices it up with [[LaserHallway Boltpairs]], [[BoobyTrap Ice Architects,]] and [[{{Fireballs}} Flamespewers]] en masse, and populates them all with numerous enemies ready to block your progress and knock you into pits. On top of ''that'', probably a good 80% of the level is made up of said platforming elements, which means that when you DO fall into a [[NonLethalBottomlessPit bottomless pit]], the spot [[BottomlessPitRescueService you get ported back to]] - that is, the last bit of solid, safe ground you touched - is likely to be [[CheckpointStarvation a considerable distance back.]]

* PowerGlows: Glowing enemies will always drop Soul Chips, but are accordingly far more powerful than regular enemies in the level. Nina, Ace and Hawk also glows while charging their attacks.
* PowerUpFood: Brain Food Lunch increases HP, Energy while restoring the latter completely.
* PrivateMilitaryContractors: The Contractors are heavily implied to be one: the opening cutscene has Dr. Sharp calling them for help with the robot uprising, the HQ has a contract from Dr. Flat on the corkboard, a run of the game is called a Job. The in-universe lingo for the types of robots Nina and Ace are is a Contractor. [[spoiler:Subverted. Nina and Ace aren't actually hired guns; they're just programmed to think they are, so they have a motivation to go on the missions.]]
* PuzzleBoss: A downplayed example. You can, of course, wail on every boss the old-fashioned way, but certain bosses aren't directly weak to the power they're supposed to be, so you have to figure out the trick that exploits the boss's REAL weakness. [[spoiler: Use Vera to reflect Kur's quint lasers back at him, and Eternal Star's minions cause a chain-reaction explosion when killed with Force Nova.]]

* ReluctantMadScientist: [[spoiler: Dr. Sharp, who mostly wanted to create successful artificial life capable of apparent humanity but works with his much meaner partner because it's the only way he can get funding.]]

* SequenceBreaking: Having any foot armor part can allow players to skip some parts of certain level with ease.

* SequelHook: [[spoiler:After completing Dr. Flat's entry in the [[FlavorText datalore]] by beating him for the third time, said datalore entry reveals that the Board is aware of Nina and Ace's escape, and are planning on taking them back by force. 1000 years later when the sequel actually takes place, they've apparently failed as Nina and Ace are still active.]]
* SetBonus: There are four armor sets in the game, each with four pieces - head, arms, torso, and legs.

** The Patchwork Connector lets you grab the bonus with only three pieces, leading to some weird and potentially very strong arrangements - given a ''perfect'' starting seed, for example, one could have Dracopent's legs, helmet and torso, allowing all shots to be charged, but Armatort's weapon, allowing you to fire an unlimited number of charge shots that cut through enemy projectiles.

* ShortRangeShotgun: The Scatterblast for Nina. The multiple projectiles make it strong up close, but weaker at longer ranges, and they dissipate faster - although charged shots have longer range, and a double-charged one will fire more projectiles as well. Nina with the arm core enhancer and a full Dracopent set is basically instant death to anything within about twenty feet of her except for bosses, and even those don't have much fun.

*** Dr. Brighton Sharp and Dr. Arlan Flat take some design cues from Dr. Light and Dr. Wily from the Classic Mega Man series. Sharp for his rotundness in comparison to his partner, and Flat for his [[EinsteinHair weird hair spikes]]. They're also named after musical terms, like most of the main characters from the Classic Mega Man series.
*** The Splinterfrost functions like a combination of the Freeze Cracker from ''VideoGame/MegaMan7'' and the Shotgun Ice from ''VideoGame/MegaManX1''. With the former, the [[http://20xxwiki.batterystaplegames.com/images/a/af/Splinterfrost.png icon for the Splinterfrost]] resembles [[https://vignette1.wikia.nocookie.net/megaman/images/b/ba/MM7-FreezeCracker-Art.jpg/revision/latest/scale-to-width-down/250?cb=20100724043500 the official art for the Freeze cracker]], and for the latter you [[PowerCopying obtain it from a penguin themed boss]] who doesn't really use the weapon himself.

*** [[spoiler:The game ends with a space station blowing up, and the final cutscene has a shot of Nina's helmet left in the sand. It's a giant reference to ''VideoGame/MegaManZero 4'''s ending, though it does subvert the original BolivianArmyEnding by panning the camera right to reveal that Nina just left her helmet and that both her and Ace are perfectly fine.]]
** Nina's Wave Beam upgrade shares it's name and appearance with the Wave Beam from the ''{{Franchise/Metroid}}'' series.

** The Ninja Sash's artwork features a headband with an insignia-inscribed metal plate bolted to the front. [[{{Manga/Naruto}} Sound familliar?]]
*** It makes you run faster and its description says [[{{Anime/SonicX}} "Gotta go fast"]].
** There's a PowerupMagnet aug shaped like [[{{ComicBook/Magneto}} Magneto's helmet]].

** Another possible end-of-run message is [[VideoGame/ChronoTrigger "But...the future refused to change."]]

** The Vibroreserve is a potato battery that looks exactly like [=GLaDOS=] in her potato body from VideoGame/Portal2.

* SuspendSave: After defeating the boss of every level you have the option to save and continue later in case you need.
* TakeYourTime: There's no ''actual'' pressure to hurry up or anything [[spoiler:during the final {{escape sequence}}.]] There's no timer to speak of, and the [[spoiler:wall of explosions behind you will never actually overtake you if you dawdle. In fact, it will actually ''retreat'' if you fall back for whatever reason. Just don't take too long. The explosion wall's hitbox will advance slowly, and deals ''double damage'' to you if you get caught in it.]]

* TooFastToStop: Collect one too many speed augments like Ninja Sash, Hypersash and you'll find out that controlling your character will become nearly impossible.

* VideogameDashing: All characters are capable of this. Oxjack's armor set in particular is focused around improving this ability, granting you a projectile-negating shield while you dash and also giving you up to three air-dashes.
* VideogameCaringPotential: [[spoiler:Al has been caged up during the EscapeSequence, and you can choose to free him by breaking the cage, or [[VideogameCrueltyPotential leave him trapped inside the exploding space station]].]]

* WhamShot: If you didn't get the hint that [[spoiler:Dr. Sharp and Dr. Flat are the ''true'' villains]], then you're in for quite a shock when you enter the Stage 9 boss arena [[spoiler: and find Dr. Sharp waiting for you in a suit of PowerArmor.]].
* WallJump: Works like it does in the ''Mega Man X'' series, though it's tweaked slightly - jumping off a wall no longer pushes you away and you don't stop for a moment when jumping onto a wall, so wall scaling becomes far more fluid. One pickup even lets you stick to a specific point as long as you're pressing against the wall.
* WeaponizedOffspring: Eternal Star is very fond of this spamming dozens and dozens of small Flapps to attack you as the battle rages on.

* YetAnotherStupidDeath: It's not unusual for players to bite more they can chew and try to fight more enemies they can handle and get mauled to death. If Rock challenge skull is active sometimes the player can forget most stage hazards are now are insta-death and end up getting themselves killed too.
** It's possible to kill yourself by picking augments that decrease your maximum health (Glass Cannon, Leafmetal Plating...) if you don't have any armor points on you.

* YouHaveOutlivedYourUsefulness: [[spoiler:Nina and Ace recieve "payment" [[WhyAmITicking (detonated)]] if you fail a run before reaching Level 4. Die after Level 4 (but before Level 9) and Drs. Sharp and Flat will instead reward them with a well-deserved "vacation" [[ThrownOutTheAirlock (flung out into space)]]. Justified, in that they are trying to perfect the bodies of the two, and if you lose, obviously they need to get [[BodyBackupDrive new bodies]] ''somehow''...]]

* Instant180DegreeTurn

* VideoGameLives: They're only available in Reverent (Easy) Mode, though.
* VideogameSettings: Naturally. RecurringLocation happens for every 2 of the initial 8 bosses.
** PlayerHeadquarters: The Ark. Where Nina and Ace resides.
** BonusStage: The Glory Zones
** AbandonedLaboratory: Twin Astrals and Death Lotus' stages.
** SlippySlideyIceWorld: Shatterbeak and Vile Visage's stages.
** FloatingContinent: Eternal Star and Kur's stages.
** EternalEngine: Perforator Alpha and Rollster Beta's stages.
** SpaceZone: [[spoiler:Dr. Brighton Sharp and Dr. Arlan Flat's]] stages.

** The items you get in a run are random, either as loot drops or as items found in shops and Very Safe Labs. This can make unlocking {{Set Bonus}}es a crapshoot, since you're not at all guaranteed to find all of the Core Augments in a set. The Patchwork Connector aug and Patchwork Integrator Prototype Augment can help with this...if you can find them, since they are also found at random, and the latter still carries a stat penalty that you'll have to work around.

* AwesomeYetImpractical: [[SetBonus Set Bonuses]]. Collecting all the armor parts from one set will give the wearer immensely powerful abilities, see the entry for SetBonus down below. However, it's incredibly difficult to obtain all the Cores from a set in one run, [[LuckBasedMission mostly due to the RNG being finicky]].[[note]]''Some'' of the randomness can be relieved using the Undevelop - a feature unlocked after buying all items with Soul Chips - which allows you to delete augments you don't want to appear in the next run, Core Augments (armor pieces) included. It also becomes less of a problem with the Patchwork Connector, which reduces the number of matching Core Augs needed for a set bonus by 1; unfortunately, the Patchwork Connector is ''also'' a random drop. In addition, there's also a more powerful version of the Patchwork Connector, the Patchwork Integrator, that makes it so that you only need two Core Augments for a set bonus (and also giving you the potential to get two set bonuses). However, as it's a Prototype Augment, not only can you only get it from Very Safe Labs, it also causes your attacks and Powers to deal 60% of the damage they normally do.[[/note]]

* MythologyGag: Early builds of ''20XX'' had a [[http://20xxwiki.batterystaplegames.com/images/9/94/Vile-Spider-Animated.gif spider robot boss]] that was eventually DummiedOut and replaced by Vile Visage. [[spoiler:[[https://steamuserimages-a.akamaihd.net/ugc/865108837549389717/1D999B8A9BB09FA84F3850A5EA36666E0D7C8ACD/ Dr. Arlan Flat's spider mecha]] bears a very strong resemblance to it.]]

* {{Expy}}: Given that the game is inspired by ''VideoGame/MegaManX'', of course Nina and Ace would be clones of X and Zero, respectively.

* {{Expy}}: Given that the game is inspired by ''VideoGame/MegaManX'', of course Nina and Ace would be clones of X and Zero, with Ace's design also taking up after [[VideoGame/MegaManClassic Protoman]].

* {{Expy}}: Given that the game is inspired by ''VideoGame/MegaManX'', of course Nina and Ace would be clones of X and Zero, with Ace's design also taking up after [[MegaManClassic Protoman]].

* {{Expy}}: Nina is one of X, down to the blue armor and long-ranged buster weaponry. Similarly, Ace has red armor and melee weapons just like Zero. Averted with Hawk, who has her own unique play style that doesn't resemble any character from the ''Franchise/MegaMan'' games.
** Without her helmet, Nina also resembles [[{{VideoGame/RokkoChan}} Rokko Chan]].

On February 13, 2020, Batterystaple announced ''30XX'', a DistantSequel set 1000 years later, with a release date of "30XX" (really 2021).

* BulletHell

** At the end of runs, there will be a brief comment on your run quoted from a supposed department. One such comment is [[{{WesternAnimation/Futurama}} "It's bad and it should feel bad!", and is listed as being said by "WOOP WOOP WOOP"]].

** The Datalore entry for the Twin Astrals gives them the nickname "The VideoGame/{{Touhou}} Twins", a reference to the ''Touhou Project'' series of games, infamous for the sort of BulletHell the Twin Astrals subject you to.

* BoringButPractical: N-Buster for Nina and A-Saber for Ace are not the most exciting weapons of the game but are generally well-suited for most situations. Likewise Hawk's whip, the Siphon, is not terrible to the point of being considered an EmergencyWeapon, but is by far and away her most "boring" weapon.