History VideoGame / ThunderForce

** ''Thunder Force AC'' (Arcade, 1990) -- An arcade port of ''III'' (unusual in that ports generally go from arcade to console and not the other way around), but with altered 4th and 5th stages. Ported to the Saturn via ''Thunder Force Gold Pack 2'', with an autofire feature that was not present in the original version. and later to the Nintendo Switch as part of M2's ''SEGA Ages'' series of Genesis ports.

** ''Thunder Force AC'' (Arcade, 1990) -- An arcade port of ''III'' (unusual in that ports generally go from arcade to console and not the other way around), but with altered 4th and 5th stages. Ported to the Saturn via ''Thunder Force Gold Pack 2'', with an autofire feature that was not present in the original version.

* ''Thunder Force IV'' (Genesis/MD, 1992) -- Released as ''Lightening ''(sic)'' Force: [[MarketBasedTitle Quest for the Darkstar]]'' in North America. Ported to the Saturn via ''Gold Pack 2'', with less slowdown and ''III''[='=]s player ship as an unlockable ship, and later to the Nintendo Switch as part of M2's ''SEGA Ages'' sereies of Genesis ports.

* DifficultyByRegion: The Japanese version of ''AC'' (which is the version used in ''Thunder Force Gold Pack 2'') is more difficult than the "World" release, Mostly, everything has twice as much health.

* SecretCharacter: Styx is unlockable in the Saturn and Switch versions of ''Thunder Force IV''. In both case, you need to beat the game once on the stock settings with the former also require the player to input a code [[note]]Press '''st'''art while '''Y''' and '''X''' before starting the game[[/note]] after the unlock condition is met

* GratuitousForeignLanguage: ''Two'' in ''Thunder Force VI'' -- an obscure and obsolete offshoot of Chinese called Tangut, and Mongolian.

* InternalHomage: ''Thunder Force VI'' has many references to past games in the series. [[TropesAreNotGood Perhaps too many.]]

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** ''Thunder Force VI'' has you fight Vasteel Nocht, which assembles giant versions of the Styx, Rynex, and Gauntlet. Notably, ''VI'' has the Rynex-R as an unlockable ship, making it the closest in the series you can get to a MirrorBoss.

** Occurs again in ''VI''. If player chooses the Phoenix fighter, it will become the Syrinx in last stage. For Brigandine, it [[DemotedToExtra only appears in the intro movie]].

* GuestFighter: The ''SEGA Ages'' port of ''IV'' lets you unlock the Styx from ''III'' to play as.

* AIIsACrapshoot: Main plot of ''V''. Humanity built a super computer named Guardian to study the wreckage of Rynex, the 4th game's Fire Leo. It then built a large fleet of starships based on the data. Then Guardian's AI damper program mysteriously disappeared and it turned against humanity with said fleet. [[spoiler:Subverted. Guardian is still loyal to humanity. Khaos (the BigBad from the previous game) escaped its destruction by transferring its program to Rynex, which deleted the AI damper after Guardian accessed its history logs. In the end, Guardian reveals that it helped humanity by purposefully spreading its forces thin and leaving critical flaws in its tactics, allowing the protagonist, Cenes Crawford, to destroy the fleet.]]

* ArtificialHuman : Cenes Crawford, PlayerCharacter of ''V'' is actually a clone of a dead AcePilot. Same as C [=CTNs=] C of ''VI''.

** The boss subname for A3 in ''V'' is often accused of this because it sounds odd at first ("It died three times, and was reborn twice"), [[GameplayAndStoryIntegration until the player realizes A3 transforms into three different modes during the fight]].

** In ''VI'', you get a siren and your ship's computer alerting of the boss in [[GratuitousForeignLanguage Tan]][[ClassicalTongue gut]], followed by the name and description of the boss, both in English and Mongolian.

* FiveBadBand: In ''VI'':
** BigBad: ORN Emperor
** TheDragon: ORN Faust/Vasteel Nocht
** EvilGenius: Cherub Purple
** TheBrute: Gargoyle Perfect and B3 (Barbaric-Berserk-Beast)
** DarkChick: Flame Maiden

* HistoryRepeats: In the bad ending of ''V'', this trope is why [[spoiler:the Guardian begs Cenes to destroy the Vambrace that she's piloting. However, she's unable to because it's too crippled to self-destruct, implying that this trope ends up happening for real.]]

* ItsUpToYou:
** ORN's forces are so much greater than the Galaxy Federation's that if the Fire Leo fails, their regular forces won't stand a chance.
** Subverted in ''IV'' where other Galactic Federation fighters team up with you to take on the Cerberus battleship before the trope gets played straight in the boss fight immediately following and for the rest of the game.
** Subverted in ''V'' in that your character leads a squad of RVR-01 Gauntlets (named "Thunder Force", incidentally). Later on, after the battle at Babel only the [[PlayerCharacter protagonist]] takes on the Guardian as only one model of the RVR-02 Vambrace is operational; [[AllThereInTheManual Cene Crawford's report]] mentions that her squadmates essentially drew straws.

** The player's RVR-01 Gauntlet upgrades to the RVR-02 Vambrace in ''V'', which has superior weapons. As well as the [[MechaExpansionPack Brigandine module]], a [[SwordOfPlotAdvancement super durable part that supplys unlimited use]] of SecondaryFire. Although the Brigandine [[TooCoolToLive only lasts for one stage]].

* OneManArmy: In most of the games, but deconstructed in ''V''. :As it turns out, the reason Cenes Crawford was even able to take on the Guardian's forces, let alone the Sword Fleet ''at all'' [[spoiler:was because the Guardian, still loyal to humanity despite Khaos compromising the AI's control, intentionally pursued HollywoodTactics and left open gaping holes for Cenes and her squadmates to exploit. All so she could commit what amounts to a SuicideByCop.]]

* RoboSpeak: Any time you collect a weapon power-up.

* SingleBiomePlanet: The sole exception is ''V'', which occurs on Earth. The ocean planet in ''VI'' is justified; it's a post-global warming world and you will get to pass the submerged city at one point. The jungle is really an abandoned space colony, with overgrown forests having overtook residental area.

* WaveMotionGun: The Rynex's Thunder Sword

* ''Thunder Force IV'' (Genesis/MD, 1992) -- Released as ''Lightening ''(sic)'' Force: [[MarketBasedTitle Quest for the Darkstar]]'' in North America. Ported to the Saturn via ''Gold Pack 2'', with less slowdown and ''III''[='=]s player ship as an unlockable ship.

* InsignificantLittleBluePlanet: In a way in ''VI''- the Galaxy Federation would only know of the existence of Earth thanks to Rynex finding its way there by chance [[spoiler:and the crew of Rynex vouching for the trustworthiness of the people of Earth]]. Granted, Earth forces do not disappoint and end up becoming TheCavalry for the Galaxy Federation.

* InsignificantLittleBluePlanet: Averted in ''VI'', with Earth forces acting as TheCavalry for the Galaxy Federation.

** In ''II'', a siren plays when encoutnering a midboss in a horizontal-scrolling segment. A lower-pitched one plays when facing the stage's endboss.

** ''Thunder Force IV'' has [[spoiler:the Rynex being crippled in the escape from the explosion following the defeat of Khaos and being abandoned to drift in space, while the scientists of the Galactic Federation admit that sending it in the first place was a mistake in and of itself. It also hints at its incipient return. Yet they still have hope for humanity's future.]]

A ShootEmUp series by Technosoft, which started with an obscure Japanese computer title in 1983 as a multi-direction overhead view shooter. It eventually become a side-scrolling shooter in the third installment, famous for its loads of [[AwesomeMusic/ThunderForce Awesome Music]].

The ExcusePlot puts player in shoes of the [[HumanAlien Galaxy]] [[TheFederation Federation]]'s [[OneManArmy pilot]] in the ''[[SuperPrototype Fire Leo]]'' starfighter against the overwhelming cybernetic [[TheEmpire ORN Empire]]. ''Thunder Force V'' [[AndNowForSomeoneCompletelyDifferent changes the focus to Earth]] when Earthmen discover the wreck of ''Thunder Force IV'''s Fire Leo (Rynex) and reverse engineer it. The Guardian, an AI designed to study Vasteel (as Rynex comes to be known), however, goes haywire on humanity, but not before they create their ''own'' Vasteel starfighter. ''Thunder Force V'' is also known for having more story than the previous games, which ties together the events of ''IV.'' The sixth installment was trapped in DevelopmentHell for a decade, but eventually released.

* ForMassiveDamage: Many of the bosses in the series requires you to strike a weakpoint

* SoundtrackDissonance: ''VI'' has unusually cheerful music for [[https://www.youtube.com/watch?v=-qx69cCE7Vs Stage 5]] and [[https://www.youtube.com/watch?v=S0SyGhQLrDQ Stage 6]], if you're using the Rynex-R or Syrinx. Both tracks are by Motoaki Furukawa, who composed several ''VideoGame/{{Gradius}}'' soundtracks that also include holiday-esque final stage music.