* AdaptationDisplacement: Subversion - most fans who are aware of the two-player BeatEmUp version of the arcade believed it came before the first UsefulNotes/NintendoEntertainmentSystem game. In reality, the arcade version was developed simultaneously with the NES version; the two development teams making their own game based its core design on the same concept.
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* AngstWhatAngst: In ''Ninja Gaiden III'', [[spoiler:upon being freed from the mask's control of his mind, Theodore Higgins doesn't seem to be fazed at all by all of the horrible things he was forced to do as the "Regent of the Mask", or the fact his brother and grandfather were the ones who forced him to do it, OR the fact his daughter is serving as the core for a giant monster ravaging Tokyo. Subverted in his last duel against Ryu Hayabusa as Theodore implies he was aware of everything that was going on while he was the Regent of the Mask. He sacrifices himself not only to allow Ryu to free his daughter, but to receive his "[[MercyKill atonement]]" for his crimes as well]].
* AntiClimaxBoss
** Although he's built up as TheDragon of the Vigoor Emperor and the Greater Fiend who destroyed the Hayabusa Village by himself, Doku in the modern ''Ninja Gaiden'' is incredibly easy due to fixed attacks patterns; unlike Alma, his maneuvers are predictable and telegraphed. Even on "Master Ninja" difficulty of ''[[EnhancedRemake Ninja Gaiden Black]]'' is the fight against Doku [[http://www.youtube.com/watch?v=TobceDp3fho pathetically easy]].
** Zigzagged with the FinalBoss of the Xbox ''Ninja Gaiden'': [[spoiler:the Dark Disciple]], who claimed to have the power of the "Devil Incarnate", can be taken down through repeated use of the "Flying Swallow" technique when using the True Dragon Sword, which was a GameBreaker in the original release. However, ''Ninja Gaiden Black'' re-balanced the boss via {{Nerf}}ing the Flying Swallow.
** Considering roughly 70% of the game is spent chasing her down, Elizabét in ''Ninja Gaiden II'' isn't much of a challenge either, except her ThatOneAttack (see below): like Doku, her moves can be easily telegraphed and she often leaves her defenses open for exploits more than the other Greater Fiend bosses in the game. ''Sigma II'' rectified it by re-balancing her with the Greater Fiends and like the FinalBoss of the modern ''Ninja Gaiden'', spamming the same attacks from weapons won't do any good, including the Flying Swallow.
** The FinalBoss in ''Ninja Gaiden III'': not that the fight isn't visually impressive, but 30% of it is fighting {{Mook}}s [[FlunkyBoss the boss sends at players]], 30% are [[PressXToNotDie quick-time events]] with the remaining 40% the ''actual'' fight. Furthermore, the latter is fundamentally the same boss fight as the Statue of Liberty boss in ''Sigma II'', which veteran ''Ninja Gaiden'' players have no problem against, making this FinalBoss arguably the easiest one in the modern trilogy. Averted in ''Razor's Edge'' when it becomes part of ThatOneBoss for the game.
* AssPull: Obaba's comeback in ''Sigma II'' and ''III''. The games don't bother explaining how she is revived when she's supposed to be KilledOffForReal in ''Dragon Sword''.
* AuthorsSavingThrow: To say that fan reception of ''Razor's Edge'' is much more positive than the original version of ''III'' is an {{Understatement}}.
* SugarWiki/AwesomeMusic: Has its own [[AwesomeMusic/NinjaGaiden page]]
* BigLippedAlligatorMoment: At the end of Day 5 in ''III'', a [[AttackOfTheFiftyFootWhatever colossal Obaba]] interrupts Ryu and Momiji who are on the way to see Joe Hayabusa via a boss fight. Not only do her and the Black Spider Ninja Clan aren't connected to the rest of the plot, they're not mentioned after the end of Day 5. ''Razor's Edge'' rectifies this by briefly noting the Black Spider ninjas are in cahoots with the "Lords of Alchemy" (LOA), yet the reason remains vague.
* BrokenBase: ''Sigma II'' - some consider it inferior to ''Ninja Gaiden II'' because of the lack of gore, lessened difficulty and the removal of puzzles, but others consider it superior thanks to a more balanced stage designs, less cheap AI, frame-rate fixes and the removal/revision of the most tedious passages of the original, as well as additional content of playable characters and game modes. The drastically reduced number of enemies and the introduction of a semi-automatic aim for the bow can be seen as a good ''or'' bad thing depending on who is asked.
* CompleteMonster: In a series featuring demon lords and other unholy terrors as villains, BigBad [[spoiler:Clifford "Cliff" Higgins]] from the third game of the modern trilogy comes off as one of the most evil opponents Ryu has ever faced. [[spoiler:[[BitchInSheepsClothing Cliff seems like a helpful scientist working for the Japanese Defense Force]]]] at the start of the game, but reveals himself as TheMole working for the LOA, a group that wants to destroy the human race and replace it with new "perfect" god-like beings. Incidentally, he's also the grandson of the head of the LOA. [[spoiler:When Cliff's brother Theodore opposed their plans, Cliff [[CainAndAbel had him and his wife Saya killed]] in an [[MakeItLookLikeAnAccident accident]], resurrects Theodore yet [[BrainwashedAndCrazy brainwashes]] him and [[TheManBehindTheMan turns him into a terrorist]]. Under Cliff's control as the Regent of the Mask, Theodore launches a terrorist strike on London and murders the British Prime Minister. His plans come to a head when he uses LOA technology and Ryu's Dragon Sword to turn Theodore's daughter [[ChildrenAreInnocent Canna]] into an EldritchAbomination called "the Goddess", who proceeds to rampage across Tokyo and will eventually destroy humanity]]. After a fight with Ryu and a fatal injury [[spoiler:from Theodore]], the BigBad admits he did all this because he was [[DrivenByEnvy jealous of his brother and wanted to step out from under his shadow, any way he could]].
* ContestedSequel: Yosuke Hayashi's drastically different vision for ''III'' left many fans skeptical. While some players believe it's still a fun ActionGame in its own right, if not, on par with the first two games, others prefer to pretend it never existed. Interestingly, Hayashi was already involved in [[VideoGame/MetroidOtherM another]] ContestedSequel.
* CounterpartComparison: In comparison to another ActionGame, ''Ninja Gaiden III'' is seen by some fans as the ''VideoGame/DevilMayCry2'' of the modern series.
* CrossesTheLineTwice: ''Ninja Gaiden II'' is so ridiculously gory it practically skips the offensive and goes straight to hilarious. May or may not double as NarmCharm.
* DemonicSpiders
** Birds or any sort of avian/winged enemy in the NES trilogy. A large reason why they're so terrible, at least in the first game, is due to a glitch with how the game handles enemy spawns: anything that's in the exact position of the level will respawn as soon as it's taken out, causing them to infinitely respawn until players deliberately trek across the stage. The problem is, particularly in the first game, moving forward is not always a reasonable option.
** The "ghost piranhas" infesting the labyrinth in Zarkhan for the Xbox ''Ninja Gaiden'' due to pack-like tendencies, respawning capabilities and sheer, unimaginable attack speed and tenacity. Hilariously, they were originally decorative in the environment until director Tomonobu Itagaki found out about them and told the development team to make them enemies.
*** Their difficulty is slightly toned down in the sequel, with the exception of that one chapter where players must deal with them ''alongside'' the Water Dragon boss. However, this becomes noticeably easier in ''Sigma II''.
** In the first game, especially at the highest difficulties, a good portion of the non-human {{Mook}}s turn into this. The black "laser eye-firing" fiends or the cat-based fiends are just ''hellish'' to fight in groups.
** ''Ninja Gaiden II'' has a ''literal'' kind with Black Spider Ninja Rasetsu. While he certainly doesn't count in his first appearance as a boss for the first level of the game, his derivatives turn into [[DegradedBoss common enemies]] later on, which do apply.
** Liked the GoddamnBats in the first Xbox game? In ''Ninja Gaiden II'', meet the giant bats! They are thrice as big, deal thrice as much damage, are thrice as tough and are still unblockable. More often than not, players will take damage while trying to kill them.
** The infamous Incendiary Kunai ninjas from ''Ninja Gaiden II'' are usually this when fighting them in large groups; [[BulletHell take a guess why by looking at their name]]. Strangely, ''Sigma II'' kept them as this despite fewer on-screen enemies at a time, but for a different reason: though they use their explosives less often, they turn more resilient to attacks (an "[[SpinningPiledriver Izuna Drop]]" won't be enough to kill them at higher difficulties) and are much more competent at close combat instead. This turns especially jarring at higher difficulties where their claw attacks deal huge damage.
** Alchemists in ''Ninja Gaiden III'' has a GroundPound-like maneuver that, while blockable, breaks guard and is hard to dodge most of the time. Furthermore, they're fast, agile, hurl homing "alchemy projectiles", block and evade often and frequently erect an "alchemy armor" of sorts that requires breaking it first before actual damage can be dealt, which light attacks from Ryu's weapons won't usually do; they also have a grab attack that not only slowly drains {{Hit Point}}s, but the ki gauge as well. Finally, in ''Razor's Edge'', the timing to perform a "Steel-on-Bone" CounterAttack is so exceptionally narrow compared to other humanoid enemies in the game that players will often opt out to dismember them instead, allowing an "Obliteration Technique" to finish them off.
** Chimera in the later parts of ''Ninja Gaiden III'' are essentially faster, more evasive Incendiary Kunai ninjas, with the only saving grace is they don't have projectiles. Like alchemists, they too block occasionally and might get a bead on escaping out of players' attack combos more often than not. The problem with these Chimera comes if they're dismembered: doing so, and they initiate an unblockable SuicideAttack, homing straight for Ryu, forcing players to prioritize on dismembered Chimera lest they risk a chunk of health getting taken away. Fortunately, it's easy to note if a suicide-Chimera will begin its strike as they start sparking bright colors; additionally, if they don't reach Ryu in time, the suicide-Chimera will wind up exploding and doesn't have the effects of an ActionBomb would.
* EightPointEight: IGN's '''3.0''' of ''Ninja Gaiden III'' gained quite a backlash. The UpdatedRerelease ''Razor's Edge'', however, got a much more decent 7.6.
* EnsembleDarkhorse: [[{{Badass}} Robert T. Sturgeon]] in ''The Dark Sword of Chaos'' is a MysteriousInformant[=/=][[MysteriousProtector Protector]] with an agenda of his own, wears CoolShades and able to take down demonic horrors with a single gunshot, [[spoiler:who turns out to be a top United States Army operative and an extremely loyal ally to Ryu that he makes a LastStand to guard his back in the very bowels of Hell]]. This is especially notable considering how ''[[SarcasmMode well]]'' Ryu gets along with covert government agencies...
** Following their respective debuts, Rachel and Momiji. They garnered enough popularity to [[CanonImmigrant immigrate]] as {{Playable Character}}s in ''Franchise/DeadOrAlive'' and the UpdatedRerelease versions of ''VideoGame/WarriorsOrochi''.
* EvilIsSexy: Elizabét
* FanonDiscontinuity: ''Ninja Gaiden III''
* FashionVictimVillain: The Regent of the Mask - having an outfit consisting of a red BadassLongcoat, a CoolMask, a [[InTheHood mysterious hood]] and a gold-plated GlovedFistOfDoom can only make him one. To compliment this trope, he's armed with a RoyalRapier.
* GameBreaker
** The Windmill technique from the NES ''Ninja Gaiden'', capable of killing every single enemy (and boss) in the game with one use, [[AwesomeButImpractical that is, provided players can plow through an entire level heading towards the boss with minimal jumping attacks or getting other power ups, as each jumping attack triggers the Windmill technique and eats up ninpo power]].
*** It's still possible to execute a normal jump attack by holding down while attacking.
** The Unlaboured Flawlessness in the Xbox ''Ninja Gaiden'' for players skilled enough to stay alive at 15% health can cut enemies down with shocking speed (most of them at any rate). Then again, given the [[DesperationAttack strict health requirement]] and the game's difficulty, this isn't as severe as the others listed.
** The Izuna Drop in all modern appearances is fairly easy to execute and will instantly kill any human-sized {{Mook}}. In the first game, enemies often block and players can only perform the technique with "katana-like" weapons, making its use restricted. However, the sequel ensures almost all weapons have access to an Izuna Drop of one form or another, and enemies don't guard at all from it. Rectified in ''Sigma II'' by {{Nerf}}ing it slightly via making some {{Mook}}s (almost all of them on Master Ninja difficulty) resilient enough to survive it.
** "Ultimate Techniques" in the modern games are a similar case: in the first game, without absorbing essence to speed it up, it takes seconds to charge a full-powered Ultimate Technique and their range of effect is limited. In ''Ninja Gaiden II'', it takes mere seconds to activate, with some weapons' Ultimate Techniques being ''glaringly'' over-effective on large groups of small {{Mook}}s.
** The Hurricane Packs for the Xbox ''Ninja Gaiden'' added an "Intercept" move that allows Ryu to parry any enemy's attack and counterattack with an Ultimate Technique if players can get the proper timing down. This move was so effective it ended up being removed in ''Ninja Gaiden Black''.
** The "Eclipse Scythe" in ''III'', despite its slow attack speed, can become this if used properly. With the Dragon Sword or the Falcon's Talons, players can directly repeat successful Steel-on-Bone attacks on nearby enemies. The scythe, however, has the longest reach of all available weapons in the game[[note]]The scythe and claws were DownloadableContent in ''III''[[/note]], meaning "nearby enemy" entails into "any enemy within a large, encompassing radius". As long as players don't screw up the initial Steel-on-Bone strike, taking down entire waves of {{Mook}}s can be done almost effortlessly.
*** As of ''Razor's Edge'', the scythe has taken this trope almost completely, being the only weapon used by players more than the Dragon Sword. However, it still suffers from a few drawbacks, notably a limit to the number of successive Steel-on-Bone attacks and the inertia after every regular strike of the weapon.
** The revamped Steel-on-Bone system in ''Razor's Edge'' is this, provided players take the time to properly use it.
* GoddamnedBats
** Actual bats for the modern games - these critters do annoying damage, and come in large packs. Explosive variants start showing up from ''Ninja Gaiden Black'' and onwards. Almost all enemies start as this, only to ascended into DemonicSpiders at higher difficulties.
** Bats are also regular enemies in the NES games, and they're in all respects similar to ''VideoGame/CastlevaniaI'' bats.
** Birds in the NES trilogy: while bats at least fly in a predictable pattern and usually aren't difficult to avoid, birds ''actively home in on Ryu's position'', and they're almost '''always''' by [[LedgeBats ledges and pits]]. In the first game, they take three slots off the life bar, making them the highest damage-dealers in the game that aren't bosses!
** The "jellyfish" in the Amazon level for ''Ninja Gaiden II'': sure, they don't move and are easy to eliminate with ranged weapons, but they get in the way and never. STOP. '''SPAWNING'''. Of course, the alternative is simply to swim through them...[[MadeOfExplodium at the player's own risk]].
** Dogs, the blue bugs and the human-like homunculi (pre-transformation into its "gorilla" or "snake" forms) often act as this in ''Razor's Edge''.
* GoddamnedBoss: Two examples from ''Ninja Gaiden II''
** The infamous giant worm boss at the end of Amazon level. By no means is it difficult: it's simply horribly ill-designed, as 90% of the fight ensures players are unable to see it, even when they're hitting it, due to the boss tunneling itself and popping out from any direction without a sign for players to know where. ''Sigma II'' didn't even try to make it better when Team Ninja mercifully removed it from the level, along with the entire "green tunnel" section leading up to the boss and after defeating it. Those who haven't played ''Ninja Gaiden II'' and only ''Sigma II'' wouldn't even notice its absence.
** The two "armadillo" bosses in the first underworld level. The words "CameraScrew" will mean something until players have gone through this fight, which stands in contrast to the first armadillo boss at the end of the aircraft level. Like the above, ''Sigma II'' removed it, replacing it with a fight against Marbus instead.
* GoodBadBug: In ''Razor's Edge'', Kasumi has a version of the "Cicada Surge" technique called "Sakura Madoi", allowing her to evade not only melee attacks like Ryu, but also bullets and missiles, meaning it's possible to use Sakura Madoi to teleport into areas normally inaccessible, and in extreme cases, ''out of the map''. This was fixed when the re-release was ported to the Sony UsefulNotes/PlayStation3 and Microsoft UsefulNotes/Xbox360.
* HilariousInHindsight: The fact the series is called ''Ninja Gaiden'' ("gaiden" meaning "side-story") due to RuleOfCool becomes hilarious these days now that [[Creator/{{Koei}} Tecmo Koei]] state it's a side-story to ''VideoGame/DeadOrAlive'', despite ''Ninja Gaiden'' [[OlderThanTheyThink having been around for a lot longer than]] ''Dead or Alive''.
** More hilarity ensues with ''Yaiba: Ninja Gaiden Z'', which is a side-story for the modern series, bringing the trope GaidenGame full circle.
* ItsEasySoItSucks: ''Ninja Gaiden III'' is a far cry from its punishing predecessors. It would take ''Razor's Edge'' to ratchet the difficulty back up to normal, but does keep the easier "Hero" mode as a play-style that can be selected at any time.
* MemeticMutation
** "Just a girl. Get out of here!"
** [[LargeHam Why? BUSINESS OF COURSE!]][[note]]When asked by Ryu about the cloned dinosaurs in the Day 3 level of ''Ninja Gaiden III'', the Regent of the Mask over-exaggerates his answer with these words[[/note]]
** Lovelace Gaga[[note]]An obvious reference to the character's uncanny resemblance to Creator/LadyGaga in ''Ninja Gaiden III''[[/note]]
* MostAnnoyingSound: The NES series, being very much NintendoHard, has the death jingle. Expect to hear it over ''and over '''and over again'''''.
* {{Narm}}
** The ''Literature/WorldsOfPower'' book is filled with this, starting with the acknowledgement on the first page, "Dedicated to the ninja in everyone's dad".
** The original arcade game is rife with this at the "round clear" screens of each stage. Specific mention is its premise: [[ExcusePlot a seemingly random]] [[GratuitousNinja ninja]] [[ExcusePlot who happens to be Ryu goes to America]] ("NINJA IN U.S.A.") [[ExcusePlot to beat the crap out of an evil cult]] full of hockey-mask wearing thugs, sumo wrestlers, normal wrestlers and others, all led by "Bladedamus", a descendant of Creator/{{Nostradamus}}.
** The "don't kill me mate" scene at the beginning of ''Ninja Gaiden III'' is so overdone and theatrical it winds up being hilarious instead of an intended PlayerPunch. Team Ninja must have taken notes as the scene is removed in ''Razor's Edge''.
* NightmareFuel
** About the only thing anybody knows about the original arcade machine is the circular saw from the continue screen.
*** From the same game, the shadow of Ryu behind a window at the start of every stage, with [[RedEyesTakeWarning creepy red eyes]] before he bursts through the screen and starts the level.
** Jaquio's NightmareFace in the first NES game and the Baron Spider's WhiteMaskOfDoom in ''The Dark Sword of Chaos''.
** How about the [[https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAQQjBw&url=https%3A%2F%2Fvgmdaily.files.wordpress.com%2F2010%2F05%2Fngaiden149.png&ei=lLAgVe5Myd2wBYm8gdgO&bvm=bv.89947451,d.b2w&psig=AFQjCNFoctlK78fXoaOHpM3czxC4Gcbo6w&ust=1428292096961254 Masked Devil]] from the first NES game?
** Professor Bucky-Wise's OneWingedAngel transformation in the OVA: [[BodyHorror his skin peels off and he grows a second backbone as his human features fall off]] ([[{{Squick}} his ears and eyes can be seen falling off and ''melting'', respectively]]) as he becomes a green skinned HumanoidAbomination. The apperance itself is incredibly sadistic, stabbing Ryu in the arm and crushing Irene Lew's arm when she tries to save Ryu, [[SlasherSmile all the while it's smiling]].
* OnlyTheCreatorDoesItRight: What certain fans think about the modern trilogy and one of the reasons there's so much bashing on Hayashi's games (''Sigma'', ''Sigma II'' and ''III'') - any title not directed by Itagaki can only be a pale imitation. It doesn't help that before leaving Tecmo, Itagaki specifically said he didn't like ''Sigma'', that ''Ninja Gaiden II'' was the definitive version of the game and he was the only one legitimate enough to continue the series.
* PlayerPunch: ''Ninja Gaiden III'' goes to great length to make players feel the pain of the enemies they kill, be it the brutal Steel-on-Bone mechanic or the moaning of enemies if they aren't finished off as they crawl helplessly on the ground, bleeding to death.
-->'''Crawling and bleeding {{Mook|s}}''': ''I don't wanna die...I don't wanna die!''
* PolishedPort: Played straight and subverted for ''Razor's Edge''. Apart from the addition of several weapons, upgrades, collectible items and playable characters, nearly every aspect of the ''Ninja Gaiden III'' gameplay has been improved, from combo speed to weapon responsiveness, to enemy AI, to the use of the ki bar and the revamped Steel-on-Bone mechanic, making the game much more technical; the [=PlayStation=] 3/Xbox 360 ports also corrects the frame-rate drops from the Creator/{{Nintendo}} UsefulNotes/WiiU version. Unfortunately, the game still contains unusual bugs and glitches, such as the "[[https://www.youtube.com/watch?v=430r4wx2ldg infinite karma]]" glitch.
* ScrappyMechanic: The save system in the Xbox ''Ninja Gaiden'' makes it so that if players die, they restart at the last save point, no exception. This means if they die fighting a boss, they must redo any section between the save point all the way to boss again; additional redundancy occurs if death happens at the beginning of the next chapter without having saved the game, where they must fight the boss from the previous chapter again.
** The Steel-on-Bone mechanic in ''Ninja Gaiden III'' was largely unnecessary due to it randomly activating in the middle of striking enemies and can interrupt combos. It's reworked in ''Razor's Edge'' where Steel-on-Bone is used as a form of CounterAttack to prevent enemy grabs.
* SeinfeldIsUnfunny: Someone watching the plots of the NES games today will find them {{Narm}}y and overdone with their "three {{Plot Twist}}s per second", but the trilogy back then was considered a big leap forward for video game story-telling by having cut-scenes and fully-sentenced dialogue, coming all together for a coherent plot.
* SoBadItsGood: Whatever fans think of the respective plots of the modern installments - ''Dragon Sword'' and ''III''[=/=]''Razor's Edge'' have a little more detailed ones, not that this saves the latter from being a ContestedSequel, though.
* SuspiciouslySimilarSong: Two of them in the arcade version - the second stage almost sounds like "Bad" by Creator/MichaelJackson and the second boss theme is very similar to "Iron Man" from Creator/BlackSabbath.
* ThatOneAchievement: It's literally impossible to obtain the platinum trophy for the Sony UsefulNotes/PlaystationVita version of ''Sigma II Plus'', as "Tag Mode" forces players to partner with the AI since CooperativeMultiplayer was removed. At least three missions ''demand'' two human players work in concert, which cannot happen if one of them is an AI-controlled character.
* ThatOneAttack: Two examples from ''Ninja Gaiden II''
** Zedonius' flame wall is unblockable ''and'' cannot be avoided at close range; even some moves with invulnerability frames cannot provide protection! The only thing players can do against it is casting ninpo spells, but if ninpo stocks are out, pray he doesn't use it. The only reasonable way to truly evade it otherwise is to stay the hell away from Zedonius as much as possible.
** Elizabét's "blood orbs" are similarly hard to dodge, unblockable, deals the largest damage from her arsenal of attacks, can place players into a {{Stunlock}} such that they'll be hit by the next orb AND [[CastFromHitPoints heals Elizabét the more the attack deals damage]].
* ThatOneBoss: Just about every single one of them, especially in the modern games.
** Bloody Malth in the first NES game throws lightning fast homing projectiles that are nearly impossible to dodge. Unless players have god-like timing, the fight is more than likely going to boil down to a war of attrition. Meanwhile, good luck getting to the fight ensuring Ryu has full health by the time players get to Bloody Malth.
** Murai in the Xbox ''Ninja Gaiden'', not because he's the first boss of the game, but being a WakeUpCallBoss.
** The first fight with Alma from the same game is often regarded as the toughest at that point due to aerial, agile strikes, unpredictable attack patterns, high-damage maneuvers and high-resilience to almost all weapons in Ryu's arsenal.
*** The later [[OneWingedAngel Awakened]] Alma fight is worse when these attributes are carried over.
** ''II'' has some pretty brutal bosses, but Zedonius takes the cake, especially the rematch against him in the underworld. While the other three Greater Fiend bosses should have the same difficulty, and fought in similar arenas to the original duels, Zedonius takes players on a series of rather small rock outcroppings floating in a big lake of magma. As the "[[RedBaron Ruler of Flame]]", he's fireproof; Ryu's not, and since the previous boss fight with him forced Zedonius to use primarily-ranged attacks in a relatively-confined space of a clock tower, unwary players will quickly learn this is no longer the case when he starts teleporting miles away to open up with his flames.
** The Regent of the Mask in ''III'' and ''Razor's Edge'', a {{Wake Up Call|Boss}} SNKBoss who blocks almost every attack players do, is less exploitable than other bosses in the game, and can NoSell attacks. Without careful thinking on when to strike, expect to be brutally punished for it if players don't have the patience to time their attacks correctly.
** Provided players wish to tackle "Ninja Trials" in ''III'' and "Test of Valor" in ''Razor's Edge'', Marbus, but for a different reason: due to the lack of a controllable boss camera angle (introduced in ''Sigma II'' but strangely absent in ''III''), players face him 50% of the time off-screen. Thankfully, ''Razor's Edge'' brought the feature back, but that doesn't mean Marbus still isn't as tough as he was in previous installments. Furthermore, he's riddled with glitches, which is noticeable when doing online Ninja Trials with a partner (human or AI).
** The FinalBoss of ''Razor's Edge'', in sharp contrast to its vanilla version in ''III'': the first phase of it, at the very least, is notorious for being extremely cheap and unfair (never-ending homing projectiles, infinite {{Mook}} respawns of [[DemonicSpiders Chimera]]), locks out ''all'' other ninpo spells other than "True Inferno" and forces players to grind the ki gauge in order to build it up to unleash True Inferno on the boss, as it's the ''only'' attack that will damage it to allow the next phase of the fight to occur. The first phase more or less forces players to resort to overusing the cheapest techniques available in order to pass it.
* ThatOneLevel
** The infamous 6-2 in the first NES game: 6-1 and 6-3 are extremely difficult as well, but 6-2 takes the cake for cheap deaths and one spot where players seemingly have to exploit a flaw in the programming to get past it. If players die even once on any of the '''[[SequentialBoss three final bosses]]''', they're forced to redo the ''entire stage at 6-1 again''.
** Stage 7 in ''Ancient Ship of Doom'' is by far worse: not only is it the longest of the NES trilogy, but running out of time is almost always expected of players, and borderline impossible of ensuring that doesn't happen ([[https://www.youtube.com/watch?v=rjPw3YAZzr4 this "perfect run"]] accomplishes the stage without death, yet closes with a mere ''two seconds'' remaining on the clock!) unless something kills players first.
*** More specifically, 7-1 has wind currents impeding player progress and can cause frequent plummets off the stage to death if care isn't taken. While there is a "fire wheel" ninpo spell that can be acquired, it's the only one in all three of sub-stages, and incredibly easy to lose either through dying or picking something else up by accident. 7-2, among other things, has traps looking like part of the background until players realize too late they took damage from it. Sure, there are two {{One Up}}s for this section, but the first one is difficult to get without dying in the process. Finally, 7-3 goes completely overboard with the spikes, placing them almost everywhere in screens that wouldn't be out of place in ''VideoGame/IWannaBeTheGuy''. Oh, and if players are looking for health potions, don't bother: there's not a single one in the entire stage. Perhaps the only saving grace is losing to the FinalBoss won't send players back to 7-1, but the sub-stages being so obtuse and the fact players have finite continues in this game make it much more problematic, though not one they'll have to repeat if they mess something up at the FinalBoss.
** The "Path of Zarkhan" chapter in the Xbox ''Ninja Gaiden'': not that it's particularly harder than previous chapters, but players spend most of the level swimming back and forth to solve a puzzle. Upon solving that, they must go through a long, boring swimming sequence through areas previously visited but now submerged. ''Sigma'' might have removed the puzzle and made the level more straight-forward, but the chapter favors swimming shenanigans over action sequences.
** The ElevatorActionSequence in ''Sigma II'' for Rachel's chapter, mainly because of CameraScrew issues and also because of [[DropTheHammer Rachel's melee weapon]] not being very adaptable to fight in narrow spaces. Savvy players will stand in the corner to charge up the Ultimate Technique over and over again between waves to cheese their way past the lower difficulties, but it gets complicated at higher difficulties where the upgraded flare-based Fiends are DemonicSpiders and deal ''a lot'' of damage - often {{One Hit Kill}}s in Master Ninja. Furthermore, a fully-charged Ultimate Technique is no longer a guaranteed OneHitKill on Master Ninja difficulty.
** Ayane's chapter in ''Sigma II'' is the hardest one to beat, particularly at higher difficulties, since she's the "[[FragileSpeedster fast but weak]]" character of the playable girls and the chapter sends a grab-bag of every enemy type in the game, even those which seem better-designed for heavier, more-powerful weapons. Prepare to see the "GameOver" screen ''a lot'' with her.
* TheyChangedItNowItSucks: What some fans think of ''Ninja Gaiden III''.
** ItsTheSameNowItSucks: What other fans think of ''Ninja Gaiden III''.
** ItsEasySoItSucks: [[RunningGag Also what other fans think of]] ''Ninja Gaiden III''.
** ItsShortSoItSucks: [[OverlyLongGag And what some fans think of]] the story for ''Ninja Gaiden III''.
* TheyCopiedItSoItSucks: Averted with the NES trilogy - people have noted the games copy a lot of things from ''Franchise/{{Castlevania}}'', most obviously the life bars, but most players agree the ''Ninja Gaiden'' games back then were still good in their own right despite the obvious influences. What likely helps is its {{Power Up}}s are fundamentally different from the ones seen in ''Castlevania''.
* TheyJustDidntCare: The Greater Fiends in the DownloadableContent missions of ''Ninja Gaiden III'' were merely ported from their respective games (Doku and Alma from ''Sigma'', Alexei, Volf, Zedonius, Elizabét and Marbus from ''Sigma II''). Their models weren't polished enough to be compatible with the game's engine, making them buggy and glitchy to battle against (Marbus being the worst offender). The same applies to Genshin (in his human and Fiend forms), Van Gelfs and Lesser Fiends, who are already on-disc. ''Razor's Edge'' rectifies them for the most part, although some glitches remain, notably Elizabét and Marbus (''again'').
* VillainDecay: The [[FourIsDeath Malice Four]] ([[TheBrute Barbarian]], [[RingsOfDeath Bomberhead]], [[KnifeNut Basaquer]], and [[ShockAndAwe Bloody Malth]]) become ordinary {{Mook}}s throughout the stages in ''The Dark Sword of Chaos'' and can be killed with a few hits. Granted, they're located on platforms where [[DemonicSpiders they'll most likely throw players into a pit]], but [[DegradedBoss they were major bosses]] in the first game.
** Justified in a GuideDangIt: the {{Mook}}s are sub-standard clones of the original Malice Four.
** The Greater Fiends from ''Ninja Gaiden II'' served no purpose in ''III'' and ''Razor's Edge'' than simply for gameplay purposes, appearing in Ninja Trials and Test of Valor challenges, respectively. Justified since they're KilledOffForReal, yet strangely enough, [[spoiler:Cliff]], one of the tougher bosses in ''III'', is nowhere to be found in Ninja Trials mode of the same games.
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