History YMMV / ThunderForce

** Haides is the hardest of the initial five stages of ''III'', featuring moving walls that can trap you and a high speed section out of nowhere. It is, however, the only stage out of that first five that has all of the weapon upgrades.

** [[https://www.youtube.com/watch?v=oTQIiIKummw "Metal Squad"]], the stage 8 theme from ''IV'', is a close soundalike of Loudness's [[https://www.youtube.com/watch?v=B92FJPZkfdc "Soldier of Fortune"]], right down to the solo.

* CatharsisFactor: Stage 5 of ''V''. You get a new ship with powerful WaveMotionGun weapons that can be ''used infinitely'' and then proceed to enjoy one of the easiest stages in the game, blowing the Guardian's defense forces into pieces.
%% * ContestedSequel: ''Thunder Force V''. ''VI'', much more so.

** In ''VI'', the only ship you can initially play as starts off with all of its weapons and never loses them, which by ''Thunder Force'' standards is pretty broken. In other words, ''the default ship is more broken than the unlockable Rynex-R.''
* ItsShortSoItSucks: One of the main reasons ''Thunder Force VI'' wasn't so well received.
* MemeticMutation: The [[FinalBoss ORN Emperor]] from ''Thunder Force VI'' was a short-lived meme [[GermansLoveDavidHasselhoff in Korea.]]

** ''Thunder Force V''[='=]s bad ending: [[spoiler:Cenes is subject to repeat what happened to Vasteel/Rynex, only instead of ejecting from the ship, ''she is trapped in it.'' All while [[https://www.youtube.com/watch?v=NxwvNLg_WnI frantic music]] plays and the Guardian begs her to blow the ship up, despite being unable to.]]
** The good ending as well. While heartwarming music plays, the Last Letter scene is still a bit spooky.

*** The Easy Mode ending as well. It consists of a dark screen of flashing images and the eyes of the ORN Emperor while ominous chanting in the background is heard as ORN Faust calls for Earth's unconditional surrender using a darker version of The Guardian's speech from V.
** Somehow, [=C-CTNs-C=]'s [[spoiler: (a.k.a. Cenes Crawford)]] [[http://vignette2.wikia.nocookie.net/thunderforce/images/9/9f/C-CTNs-C.png/revision/latest?cb=20141106093851 appearance]] in ''Thunder Force VI'' is a bit creepy to some people.

* {{Sequelitis}}: ''VI'' was released 10 years after ''V'', and came to be a big disappointment among fans, with only six short stages, a radically different soundtrack, excessive homages to past games, weapons as broken as ''Thunder Force V''[='=]s, and a new weapon mechanic in which you start with every weapon and never lose any of them.

** [[https://www.youtube.com/watch?v=oTQIiIKummw "Metal Squad"]], the stage 8 theme from ''Thunder Force IV'', is a close soundalike of Loudness's [[https://www.youtube.com/watch?v=B92FJPZkfdc "Soldier of Fortune"]], right down to the solo.
** [[https://www.youtube.com/watch?v=-VzLxWBho-8 "Lightning Strikes Again"]], the opening theme from ''Thunder Force IV'', is based on Dokken's song named--get ready for it--[[https://www.youtube.com/watch?v=MKF5R8doqDE "Lightning Strikes Again"]].
** [[https://www.youtube.com/watch?v=nud4FpIeNqo "Beginning of War"]], the intro theme to Thunder Force V and the Gauntlet's leitmotif, takes its riffs from [[https://www.youtube.com/watch?v=25h8mwE5ZOI "Live Wire"]] by Mötley Crüe.
** [[https://www.youtube.com/watch?v=MYbztuII3iY "Ruined Green"]] from ''VI'' sounds very similar [[https://www.youtube.com/watch?v=zDuTidfmaI4 "Geometric City"]] from ''[[VideoGame/RaySeries RayStorm]]''.
** Compare [[https://www.youtube.com/watch?v=-qx69cCE7Vs Full Speed]] from ''VI'' to [[https://www.youtube.com/watch?v=FLc1msji0_w "Burning Heat"]] from ''VideoGame/{{Gradius}}''.

* TheyWastedAPerfectlyGoodPlot: ''Thunder Force VI''- the ORN Empire has found its way to Earth despite Cenes Crawford's [[spoiler:and the Guardian's]] best efforts, Earth forces have revived the Sword Fleet just in time to make a stand at their homeworld's orbit, and their most advanced weapon, the RVR-00 Phoenix fighter with Brigadine booster, is about to deal the first blow...... and all we get from that story angle is a mere cutscene.
* UnderusedGameMechanic: ''Thunder Force V'' features a "Direct" control option that assigns each of the five weapons to its own button, alongside the traditional option of "cycle through weapon list" buttons. Direct weapon switching was sadly not kept for ''Thunder Force VI''.

** Blade in ''IV''. Normally, when you shoot an enemy, blue explosions indicate no damage and red explosions indicate damage. However, when hitting enemies with the Blade, ''all'' hit explosions are red, meaning you can fire nonstop at a boss and not realize you've been doing no damage to it all along until you're wondering "WhyWontYouDie" 5 minutes later. At least its base counterpart, the [[BoringButPractical Twin Shot]], doesn't have this problem. Even worse, when the Rynex was backported into the ''SEGA AGES'' port of ''Thunder Force AC'', the Blade kept this behavior.

* SignatureScene: Stage 5 of ''Thunder Force V'', in which the player gains access to the Brigandine module and then proceeds to ''demolish'' the Sword Fleet, culminating in a ClimaxBoss fight with [[spoiler:[[DuelingPlayerCharacters the Rynex / Vasteel Original]] from ''Thunder Force IV'']].

* SignatureScene: Stage 5 of ''Thunder Force V'', in which the player gains access to the Brigandine module and then proceeds to ''demolish'' the Sword Fleet, culminating in a ClimaxBoss fight with [[spoiler:Rynex / Vasteel Original]].

* ThatOneLevel: In ''II'', Stage 4-1 ([=X68K=]) / 3-1 (MD) is a cavern where you have to carefully navigate through mazes of red walls to get from one base to the next. The difficulty is especially pronounced in the MD version, as the old Stage 3-1 was removed, causing this stage to take its place and thus lacking a more intermediate stage where you can prepare for this one; up until this point, the DeadlyWalls were mainly sky fences, skyscrapers, or random tunnels of destructible walls in the open air, but here you are expected to carefully fly through the tunnels at such a high speed. The space where you find the final base is the most aggravating, as it's covered in destructible wall that you have to shoot through ''while'' dodging enemy fire at the same time.

* ScrappyWeapon: Blade in ''IV''. Normally, when you shoot an enemy, blue explosions indicate no damage and red explosions indicate damage. However, when hitting enemies with the Blade, ''all'' hit explosions are red, meaning you can fire nonstop at a boss and not realize you've been doing no damage to it all along until you're wondering "WhyWontYouDie" 5 minutes later. At least its base counterpart, the [[BoringButPractical Twin Shot]], doesn't have this problem. Even worse, when the Rynex was backported into the ''SEGA AGES'' port of ''Thunder Force AC'', the Blade kept this behavior.

* ThatOneLevel: In ''II'', Stage 4-1 (X68K) / 3-1 (MD) is a cavern where you have to carefully navigate through mazes of red walls to get from one base to the next. The difficulty is especially pronounced in the MD version, as the old Stage 3-1 was removed, causing this stage to take its place and thus lacking a more intermediate stage where you can prepare for this one; up until this point, the DeadlyWalls were mainly sky fences, skyscrapers, or random tunnels of destructible walls in the open air, but here you are expected to carefully fly through the tunnels at such a high speed. The space where you find the final base is the most aggravating, as it's covered in destructible wall that you have to shoot through ''while'' dodging enemy fire at the same time.

** ''Thunder Force II MD'' had to remove an entire stage from the X68000 version[[note]]More specifically, Stages 3-1 and 4-2; what was Stage 4-1 is now 3-1, Stage 3-2 is kept, and subsequent stages are bumped down a number[[/note]] as well as some graphical effects, but it plays pretty well and buffs some of the weapons (Hunter now fires faster bullets, for example) while replacing some other weapons with more useful ones (Sidewinder was changed from "Laser clone that uses missiles instead of lasers" to a far more useful vertical shot). New music tracks were introduced too, with Stages 3-2 and 4-2 now having unique tracks instead of just reusing the Stage 1-2 and 2-2 tracks.

** ''Thunder Force II MD'' had to remove an entire stage from the X68000 version[[note]]More specifically, Stages 3-1 and 4-2; what was Stage 4-1 is now 3-1, Stage 3-2 is kept, and subsequent stages are bumped down a number[[/note]] as well as some graphical effects, but it plays pretty well and buffs some of the weapons (Hunter now fires faster bullets, for example) while replacing some other weapons with more useful ones (Sidewinder was changed from "Laser clone that uses missiles instead of lasers" to a far more useful vertical shot). New music tracks were introduced too, with Stages 3-2 and 4-2 now having unique tracks instead of just [[RecycledSoundtrack reusing]] the Stage 1-2 and 2-2 tracks.

** ''Thunder Force II MD'' had to remove an entire stage from the X68000 version[[note]]More specifically, Stages 3-1 and 4-2; what was Stage 4-1 is now 3-1, Stage 3-2 is kept, and subsequent stages are bumped down a number[[/note]] as well as some graphical effects, but it plays pretty well and buffs some of the weapons (Hunter now fires faster bullets, for example) while replacing some other weapons with more useful ones (Sidewinder was changed from "Laser clone that uses missiles instead of lasers" to a far more useful vertical shot).

** Free Range in ''V''. Even the manual of the North American version describes it as the strongest weapon in the game and encourages you to use it.

* PortingDisaster:
** For some reason, ''Thunder Force AC'' has a really slow autofire rate, forcing players to furiously mash the fire button to achieve the same rate of fire as the Genesis version's autofire. And then there's ''Thunder Spirits'', a port of ''AC'' with still no autofire and lots of slowdown.
** Thunder Spirits actually has autofire, it just has to be turned on in the options menu, which for some reason is hidden instead of being obviously accessible. Ostensibly this was all to make the game more challenging. It ''does'', but probably not in the way that was intended.
* ScrappyMechanic: In ''III'' (on Normal and below) and ''IV'' onwards, getting killed takes away the weapon you have equipped, unless it's the Twin Shot or Back Shot. In practice, this means you'll frequently be using the weapon you ''least'' need when you're in situations where you feel like you have a reasonable chance of taking a hit.

* PolishedPort: The ''SEGA Ages'' version on Switch has everything you'd expect in a console-to-another-console port (screen fitting and filter options, button configuration) and M2's usual top-notch porting standards, but adds a neat new feature: you can now have voices not interrupt the background music! And if you beat the game, you unlock the Styx from ''III'' as a playable ship. Last but not least, it has perhaps the lowest amount of input lag of any shmup on the Switch, at only three frames.

* ScrappyWeapon: Blade in ''IV''. Normally, when you shoot an enemy, blue explosions indicate no damage and red explosions indicate damage. However, when hitting enemies with the Blade, ''all'' hit explosions are red, meaning you can fire nonstop at a boss and not realize you've been doing no damage to it all along until you're wondering "WhyWontYouDie" 5 minutes later. At least its base counterpart, the [[BoringButPractical Twin Shot]], doesn't have this problem.

* PolishedPort: The ''SEGA Ages'' version on Switch has everything you'd expect in a console-to-another-console port (screen fitting and filter options, button configuration) and M2's usual top-notch porting standards, but adds a neat new feature: you can now have voices not interrupt the background music! And if you beat the game, you unlock the Styx from ''III'' as a playable ship.

* {{Narm}}: The intro dialogue in ''Thunder Force II'':

* EarWorm: The option music in ''Thunder Force II'' (X68000 version), ''IV'', and ''VI'', "[[https://www.youtube.com/watch?v=5FvKczaUwI4&fmt=18 Tan Tan]] [[https://www.youtube.com/watch?v=oaAnnBw20bM&fmt=18 Ta Ta Ta Tan]]".

** [[https://www.youtube.com/watch?v=MYbztuII3iY "Ruined Green"]] sounds very similar [[https://www.youtube.com/watch?v=zDuTidfmaI4 "Geometric City"]] from ''[[VideoGame/RaySeries RayStorm]]''.

* [[https://www.youtube.com/watch?v=MYbztuII3iY "Ruined Green"]] sounds very similar [[https://www.youtube.com/watch?v=zDuTidfmaI4 "Geometric City"]] from ''[[VideoGame/RaySeries RayStorm]]''.

** ''Thunder Force V''[='=]s bad ending: [[spoiler:Cenes is subject to repeat what happened to [[strike:Rynex]] Vasteel, only instead of ejecting from the ship, ''she is trapped in it.'' All while [[https://www.youtube.com/watch?v=NxwvNLg_WnI frantic music]] plays, as if the game's begging ''you'' to self-destruct the Vambrace and there's absolutely nothing you can do about it.]]