YMMV / Ninja Gaiden (NES)

• Complete Monster: (The) Jaquio, real name Guardia de Mieux, wants to Take Over the World. Jaquio learns of a legend about a Demon that came to Earth 700 years and went on a killing spree until it was defeated by a Shinobi. The Demon's body was imprisoned in a temple and its spirit was trapped in 2 different statues. Jaquio plans to free the Demon, believing it will grant him great power. Jaquio takes over the temple ruins and kills archeologist Walter Smith and kidnaps Ryu's father Ken in order to obtain the statues. When Ryu Hayabusa confronts Jaquio, the latter threatens to kill CIA agent Irene Lew if Ryu doesn't give him the statue, planning to sacrifice her anyway after Ryu gives him the statue. When Ryu confronts Jaquio again, the latter reveals he has made Ken his mind-controlled puppet and gleefully has him attack Ryu. Ryu seemingly kills Jaquio, but the latter is revived by evil magic. Jaquio obtains the Sword of Chaos and the Altar of Darkness that will allow him to open a portal and allow a horde of demons to enter Earth, dooming mankind in the process. Jaquio attacks Ryu through his pawn Ashtar, and plans to sacrifice Irene and Ryu to summon the demons to Earth.
• Demonic Spiders: Hawks have a tendency to dive bomb Ryu, dealing three units of damage and knocking him back. They're usually placed around Bottomless Pits, meaning they can send him to an untimely death if the player's not careful. They're also very fast and can respawn because of the way respawning enemies work in this game.
• First Installment Wins: Although The Dark Sword of Chaos and The Ancient Ship of Doom introduced gameplay refinements, most people will jump back to the original NES Ninja Gaiden as it's the most recognizable of the trilogy in terms of Demonic Spiders in conjunction with Platform Hell, as well as an easier to digest plot. Beyond that, it's also the most recognizable game in the series, save for Ninja Gaiden (2004).
• Game-Breaker: The Windmill Technique from the first game, capable of killing every single Mook (and boss) in the game with one use, 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. However, it's still possible to execute a normal jump attack by holding down while attacking.
• Genre Turning Point: Ninja Gaiden is commonly considered as one of the pioneers that jumpstarted the popularity of animated cinematics in video games and especially in console games. Whereas early video games used static images and texts even in story-driven adventure games, Ninja Gaiden proved it could make a simple plot epic and grandiose by introducing frequent, animation-like cutscenes between the stages.
• It's Hard, So It Sucks!: This game is insanely hard, but normally this would do little to starting players since that's an already well-established fact for the series. However, Act 6 is where many players deem it too brutal for its own good. Unlike previous Acts where failing a boss battle only sends you back to the preceding level, dying in the final boss (who has three phases) sends you back to the beginning of Act 6, forcing to play all those insanely difficulty levels again. This has helped Ninja Gaiden gain a reputation for being one of the hardest NES games of all time.
• Self-Imposed Challenge: Pacifist and low percent challenges have been popular with challenge runners. Low percent challenges disallow items, ninpo techniques and health pickups. There's also damageless challenges, in an already difficult game.
• That One Boss: Bloody Malth in the first 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. Since the battle follows a cutscene, players start the Boss Fight with a full health bar. Because of that, the best strategy really is to just rush him and mash the attack button. It could be considered an act of mercy if there were any evidence the developers were capable of such a thing.
• That One Level: The entire Act 6, and there's a reason for grouping the levels together. Act 6-1, 6-2 and 6-3 are all extremely difficult, and 6-2 takes the cake for cheap deaths and one spot where players have to exploit a flaw in the programming to get past it. But the highlight is how checkpoints work in this Act; if players die even once on any of the three final bosses, they're forced to redo the entire Act at 6-1 again. Without use of save states, this might be the most frustrating stage in the whole series.