YMMV / Ninja Gaiden III: The Ancient Ship of Doom

• Complete Monster: H.P. Clancy is an assistant to CIA agent A. Foster and the hidden true villain of the game. After hero Ryu Hayabusa slew the evil wizard (the) Jaquio and a demon he summoned, the demon's destruction created a portal to another dimension that is releasing energy. Foster takes over what is left of Jaquio's fortress in the Amazon and renames it Castle Rock Fortress. Clancy and Foster begin to use the other-dimensional energy to perform experiments, setting up a lab to create nightmarish creatures called Bio-Noids. When Ryu's girlfriend, CIA agent Irene Lew, was investigating the lab, Clancy has a Bio-Noid that looks like Ryu seemingly kill Irene and then frames Ryu for her murder. After Ryu investigates the lab, Clancy approaches him and appears friendly, directing him to go to the Castle Rock Fortress, saying he cannot condone Foster's experiments. When Ryu confronts Foster, Clancy reveals his true intentions, he will go into the dimensional portal and claim the energy for himself. When Ryu later confronts Clancy in the portal, Clancy reveals his master plan to use an ancient alien warship to destroy humanity and replace them with Bio-Noid creatures.
• Game-Breaker: The absence of the Windmill and Doppleganger Ninpou from the first and second game allows the Fire Wheel to shine in the third. It damages enemies on touch along with making Ryu invincible for a short time. This proves extremely useful against bosses, as Ryu can use it to attack basically unpunished (in particular against the final bosses), and becomes invaluable if you keep the one you find at Act 7-1 all the way into 7-3: Ryu can use the Fire Wheel to zip through the Spikes of Doom in there without taking damage, speeding up a section of the Race Against the Clock that would otherwise heavily slow you down.
• Porting Disaster: The Atari Lynx version, while impressive, suffers from inferior graphics, bad controls and horrid music. Its also the last official game released for the system; not exactly going out with a bang.
• That One Level: Stage 7 in The Ancient Ship of Doom: not only is it the longest stage in the NES trilogy, but running out of time is always expected of players, and borderline impossible of ensuring that doesn't happen (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 of the stage, 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 Ups 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 of Doom, placing them almost everywhere in screens that wouldn't be out of place in I Wanna Be the Guy. Oh, and if players are looking for health potions, don't bother: there's exactly one health potion in Act 7-2. Perhaps the only saving grace that is unlike the first NES game, losing to the Final Boss won't send players back to 7-1, but the sub-stages being so obtuse and the fact players have finite continues in the American version of this game make it much more problematic, though not one they'll have to repeat if they mess something up at the Final Boss.