YMMV / Operation: Z.E.R.O.

  • Crowning Music of Awesome: The Opening Title, an intense remix of the series' opening theme that actually wouldn't feel out of place in a theatrical movie.
    • Grandfather's Theme really underscores the drastic situation the KND are placed in once he begins retaking over the world.
  • Jerkass Woobie: This movie singlehandedly established Father as this by giving him the biggest Freudian Excuse possible.
  • Magnificent Bastard: Grandfather wasn't always this, but his first defeat in the movie's prologue evidently taught him some lessons about being an Evil Overlord that he took to heart. To prevent the children of the world from rising against him again, he decides to turn them all into Senior Citi-Zombies, starting with the Kids Next Door; to make sure the adults of the world don't try to stop him either, he does the same to them — including the other villains of the show; even when he has more than 99% of the world under his thumb, he swears not to rest until he's destroyed the Book of KND, which was, after all, the thing that allowed Numbah Zero to defeat him before. Once he meets his rebellious son again, he declares he won't give him a choice between cooperating-or-else again and tries to bring him down.
    • Both his sons show signs of this themselves. Father brought all the adult villains of the world together and attacked the KND Museum and Moonbase simultaneously, knowing that Sector V would prioritise the Museum on Numbah 1's orders. He also knew ahead of time that the Recommissioning Module was not actually damaged beyond repair, and pre-empted that Numbah 1 would come to their Convention Centre to fetch it — and that he would come alone, without any back-up. Not only that, but he made sure that Numbah 1's "right on schedule" arrival would benefit his Evil Plan — he provided a KND operative's genetic material necessary to make the Module work. As for Numbuh Zero? He distracted Grandfather while Numbuh 1 and his team crashed the Moonbase right on top of him! It didn't kill him, but that wasn't what Numbuh Zero was trying to do — he simply wanted to get him into a Decommissioning Chamber, allowing them to De-Power him once again.
  • Nightmare Fuel: The senior citizombies' yellow pupiless eyes are quite frightening, as are the zombies themselves.
    • Each of the KND getting infected, but particularly Numbuh 362, considering that she's the strongest member of the KND.
  • Tear Jerker: Lots of it.
    • The rapid fall of the KND as Grandfather's Senior Citi-zombies spread throughout the world is truly the Darkest Hour for them.
    • Numbuh Zero purposefully broke the Recommissioning Module before being decommissioned so that he could finish the most important mission in his life: being a good father to his son, Numbuh One.
      • On a similar note, there's a brief moment shortly before Numbuh One realizes who he really is and initially recommissions him where he's dejectedly looking down after Numbuh One tells him to shut up for being a distraction and a Bumbling Dad when the former is trying to save them. You can tell how heartbroken he is to hear his son get mad at him for trying to spend some quality time together.
      • In Operation: I.N.T.E.R.V.I.E.W.S., he somehow gets recommissioned again so he can say goodbye to his son.
    • The Reveal that the Delightful Children from Down the Lane are actually "delightfulized" Kids Next Door operatives, specifically Sector Z. Also heartbreaking is the news that their return to their true selves in only temporary, and even worse is their final words when they do inevitably revert to the Delightful Children. Numbuh One can do nothing but watch and let out a Big "NO!" as it happens before his very eyes.
    Sector Z/DCFDTL: Tell... the Kids Next Door... we miss them! AHHH!!!
    • Numbuh One having no choice but to fight his brainwashed teammates, and his ultimately failed attempts to reach out to the real them, until he uses Numbuh Two's upgraded Birthday Suits.
  • They Wasted a Perfectly Good Plot: Nigel never directly interacts with his grandfather, Grandfather, and remains oblivious to their relation until he learns Father is his uncle, having been too distracted by the fact that his father was Numbuh Zero. We also have no indication that Grandfather is even aware he has a biological grandson and adoptive grandchildren. While this movie does explore the origins of the KND more in-depth, one can't help but feel that they could've done more with the Uno Family's history.