''The 3rd Birthday'' is the third game in the ''VideoGame/ParasiteEve'' series.

It was originally announced for Japanese cellphones but has since been changed to a PSP game; it got a December 2010 release in Japan and a March 2011 release everywhere else. Speculation is that the game is not billed as "Parasite Eve" because Square Enix doesn't want to pay to keep using the license -- fair enough, since due to the [[ThirdPersonShooter radical gameplay departure]] between this [[SurvivalHorror and]] [[VideoGame/ParasiteEve previous]] [[VideoGame/ParasiteEve2 titles]], it'd really matter just for the name.

Christmas Eve 2012 sees the rise of massive tentacled structures known as the Babels throughout Manhattan and other parts of the globe, spawning time-distorting monsters known as the Twisted. Fast-forward one year later, to the U.S. government's Counter-Twisted Initiative launching their campaign against the creatures using Aya Brea and her [[MentalTimeTravel Overdive ability]] to [[BodySurf insert her consciousness]] into key SWAT troopers and National Guardsmen in the past and make key strikes against both the Twisted and the Babels. But why does Aya have no recollection of her past, and what is the meaning behind her dreams of a bloodstained wedding?

For added star power, Creator/YvonneStrahovski and Creator/JensenAckles provided the voices for Aya Brea and Kyle Madigan respectively for the English version.

!!This game provides examples of:

* AKA47: Unlike the [[VideoGame/ParasiteEve previous]] [[VideoGame/ParasiteEve2 installments]], this game plays this trope straight with all guns having fictional names and model numbers.
* AndYourRewardIsClothes
* ArtificialStupidity: Soldiers whom you are not directly controlling are next to useless in battle. This includes ones who are manning machinegun turrets and ''attack helicopters'', but will not fire a single shot on their own.
* BigDamnHeroes: [[spoiler:The real Aya at the end of the game when she shoots Hyde, who it turns out is a [=HighOne=]]].
--> ''"Leave her alone, will you?"''
* BittersweetEnding: [[spoiler:Eve-as-Aya continues her work as a government agent in the alternate timeline, and most of the people killed during the events of the game are brought back and live happy lives. However, the real Aya has been [[UnPerson erased from the timeline completely]] and [[RippleProofMemory Eve is the only one who remembers]]]].
* BloodierAndGorier: While the first games had a certain amount of blood and gore (mostly during the mitochondria transformations), ''The 3rd Birthday'' appears to be ramping that up. People snatched by the Twisted are reduced to piles of gore; you're likely to feel guilty if you have to abandon one body only to hear the screams and crunches left behind by the poor soldier.
* BodyHorror: Possibly less here than in others in the series, but still a lot.
* BodySurf: A major gameplay feature. Eve is projecting herself to the battlefield via a machine called the Overdive system; she's lending her powers and mind to the soldiers she takes over and hopping from body to body is how she obtains new weapons or how to move around otherwise-impassable terrain. Trying to use Overdive on monsters doesn't allow you to take them over; however, it does damage them, in a variant on TeleFrag. It's also how [[spoiler:Eve accidentally sets into motion the events in the game]].
* BottomlessMagazines: An unlockable cheat.
* ChangingClothesIsAFreeAction: Subverted with costumes/armor. You can only change outfits(and repair them) at checkpoints or the Overdive Room. Repairing clothes costs BP too.
* CheatCode: The internal variety. Where most of the replay value lies. Beating the game a certain number of times under different difficulties and meeting the requirements of certain feats unlocks different cheats that change gameplay.
* CheckPoint: Used in two ways -- in save stations mid-mission where you can also buy/customize weapons, change armor, and customize DNA; and in checkpoints mid-level where you can restart if you die.
* ClothingDamage: The more Aya is damaged, the more her clothes will rip and fall off. This eventually cuts off when Aya's shirt and pants are essentially reduced to her bra and underwear. This is more than Fanservice: she takes more and more damage the worse her clothing condition is, so it's to your benefit to keep all her outfits repaired.
* CutsceneIncompetence: [[GameplayStorySegregation No matter how powerful]] you actually are in the game, Aya gets pushed around quite a bit.
* DeathIsASlapOnTheWrist: Due to all of the checkpoints, dieing doesn't set you back too far.
* EldritchAbomination: Many, if not ''all'' enemies in the series tend to be this, but the ones in ''"The 3rd Birthday"'' take the cake. ''ESPECIALLY'' the boss enemies. They're not called "The Twisted" for nothing; they warp out of holes in the space-time continuum and have nearly-impossible shapes.
%%* EveryBulletIsATracer
* ExpositionBreak: Whenever you talk to Maeda.
* FanDisservice: Aya has the chance to wear more sexier clothing but the game also boasts that any damage done to Aya will be visibly shown. Ergo, the swimsuit will be tattered and torn to reveal more of Aya and her scars, making it look really disgusting and creepy.
* FreeFallFight: The fight with the Queen.
* HarderThanHard: It's called "Genocide Mode" for a reason.
* HealingFactor: Aya can take hits until her clothes disintegrate, but if she takes too many before her HealingFactor kicks in, she'll die.
* HeroicSacrifice: [[spoiler:In order to prevent the creation of the Twisted and the High Ones, Aya switches bodies with Eve and has Eve (now in Aya's body) shoot Aya-- thereby cleanly killing Eve's body (the source of the High Ones), and Aya's soul (the source of the Twisted) at once]].
* HoistByHisOwnPetard [[spoiler:Hyde]]'s desire to combine with [[spoiler:Eve]] and his subsequent forcing her out of [[spoiler:Aya]]'s body was what lead to [[spoiler:his]] own demise.
* HoldTheLine: This one has more than its share of situations where you simply have to survive until reinforcements arrive. Also can happen in boss fights if you mismanage your troops and suddenly find that you're the [[OhCrap only one left on the field]].
* HopelessBossFight: The first time you encounter a Reaper, you're told to run like hell. The thing is invulnerable to your current weapons, it can FlashStep, and it creates barriers to keep you from escaping. You can BodySurf into someone on the other side of the barriers, but no suck luck for the poor soldier you leave behind.
* HumanoidAbomination: [[spoiler:The High Ones, before turning into their monstrous forms]].
* HyperspaceArsenal: Played literally straight, where Aya's gun vanishes in a flash of light whenever she switches to another one. Of course, this is because she's using a form of time travel.
* ItsUpToYou: Aya is the only one able to use the Overdive system thanks to her unique biology.
* KillSat: A few times, you're forced to encounter enemies that are all but invulnerable to conventional weapons. Fortunately, a soldier with a [[VideoGame/GearsOfWar Hammer Of Dawn]] shows up for you to possess in these situations.
* LaserGuidedKarma: The evil chief's attempt to sabotage the time-travel mission results in a new timeline where he got killed months earlier.
* MentalTimeTravel: The apparent function of the Overdive system in ''The 3rd Birthday.'' [[spoiler:Which accidentally creates the Twisted]].
* MoreDakka: What the [=T498PS=] lacks in accuracy and handling, it more than makes up for in brute power.
* TheMultiverse: Theorized by Blank in one of his emails to be the secret behind Aya's "time-travel" ability.
* NewGamePlus: UpToEleven - The game requires you to beat it several times for certain costumes, cheat codes, [[spoiler:Deadly and Genocide difficulty modes, ''and'' an unlockable alternate ending]].
* NiceJobBreakingItHero: [[spoiler:Everything in The 3rd Birthday happened because Eve Overdived into Aya to try to save her when she was nearly shot to death. The result was basically ''VideoGame/ParasiteEve'' confusingly crossed with ''Series/QuantumLeap'', with Eve confusing herself with the now dead Aya and creating a stable time loop]].
* NintendoHard: You can die a few times even during Easy mode.
* NoCutsceneInventoryInertia: Played straight. Justified, in that a meido outfit would look pretty weird in a serious cutscene.
* OutOfClothesExperience: How Aya appears in when between bodies. Naturally, BarbieDollAnatomy is used.
* PileBunker: An unlockable weapon.
* PowerupLetdown: Most of the other costumes can only be unlocked by beating the game on harder difficulties and aside from the revealing clothing, also has weaker defensive stats aside from the Lightning outfit (go figure). Fortunately for the player, the two base costumes Aya starts with have B and A grade defense.
%%* PuppeteerParasite
* ResetButton: Partially: [[spoiler:Thanks to Aya's HeroicSacrifice, a new timeline is created where the Twisted were never created in the first place. This effectively undoes the damage they caused, but at the cost of Aya]].
* TheReveal: [[spoiler:Aya Brea = Eve Brea]] throughout the game.
* RippleEffectProofMemory: Aya has this, but the rest of her team ''do not.'' This means that they have difficulty believing that Aya has time-traveled at all. As far as the team is concerned, each time is her "first" time diving into the past. This makes the BadBoss ''even worse''.
* RuleOfCool: The law that defines the entire game, arguably. And...
* RuleOfSexy: The other law.
* SanDimasTime: While Aya is in the Overdive machine, her support staff can follow her actions and give advice.
%%* SavePoint
* SexySantaDress: One of the unlockable outfits.
* ShapedLikeItself: Due to [[spoiler: Eve's soul inhabiting Aya's body through the entirety of the game]], The name "Parasite Eve" is actually pretty clever. Its a shame the game [[Main/NonindicativeName isn't actually called that.]]
* ShoutOut:
** Lots with ''VideoGame/FinalFantasyXIII'', most notable Lightning's gunblade and her outfit. It sports the best defensive stat in the game.
** For ''Franchise/FinalFantasy'' in general, there's also a helicopter named "Bahamut."
** The ShowerScene is a ShoutOut to [[VideoGame/ParasiteEve2 PE2]]
** The way the concert scene plays out is similar to the infamous opera scene from [[VideoGame/ParasiteEve PE1]].
* ShowerScene: Upgraded to soft-core porn, with Aya[[spoiler:'s body, which is inhabited by the questionably young Eve]].
* SuperMode: "Liberation", formerly a spell that wiped out nearly everything in the original installment, returns as a meter that fills up as you take or receive damage. Activating it causes Aya to FlashStep instead of walk, makes her invulnerable to damage [[note]]Reapers can still damage her, however little it does[[/note]], and makes her weapons do much more damage.
* TeasedWithAwesome: The occasional times you get to use the KillSat.
* TimeyWimeyBall: The game involves Aya using a machine that projects her into the past via a BodySurf system, and the Twisted monsters themselves appear to be invaders from another time and place due to the way they emerge from warping holes in the space-time continuum. Aya's Overdives also somehow cause a ripple effect ''backwards'' in time, where changing what happened just three days earlier changes events that happened more than a year earlier. Just to mess with your head further, Aya's memories have been damaged and she's flashing back continually.
** Taken UpToEleven by the ending: [[spoiler:Aya travels back in time to stop the event that created the High Ones in the first place, which is also the source of her Overdive ability. So basically, she uses time travel to prevent both the creation of time travel technology and the reason she traveled back in time.]]
* UniversalAmmunition: Ammo recharge points just happen to have a full stock of whatever ammo your weapons need at the time.
* UnPerson: [[AllThereInTheManual According to backstory]], Doctor Blank is an expert hacker who was caught by the US government, forcing him to erase all evidence of his existence and [[BoxedCrook come work for them]].
* TheUnReveal: The story never explains why Aya was attacked on her wedding day.
* VideoGameCaringPotential: When all deaths provide example for BodyHorror, it's hard to not care about the poor soldier/civilian whose body you hijack. The fact that number means strength in Crossfire also helps. A case of FridgeBrilliance too: you [[spoiler:that's, Eve]] is doing your namesake: being a protective mother. Without your MentalTimeTravel, they would have died left and right.
* VoiceGrunting: What you get for the few bits of dialogue that aren't voiced.
* WasOnceAMan: Implied to be the origin of The Twisted. The weakest Twisted still have human-like legs and most of the bosses are apparently humans who transform directly.
** Even [[{{Squick}} worse]] with [[spoiler: the High Ones, who can take human form]].
* WeCanRuleTogether: [[spoiler:Hyde]]'s offer to Eve.
* WhatHappenedToTheMouse: The identity of the armed group that attacks Aya's wedding is never revealed, despite them arguably [[UnwittingInstigatorOfDoom being responsible for the entire plot]].