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

• Awesome Music:
  • 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 is the greatest threat the Kids Next Door's entire organization has ever faced in history. An ancient evil who once reigned supreme over the world, Grandfather was supplanted only when one of his own sons betrayed him and stole his powers and memories. Years later restored to his former glory, Grandfather immediately turns the most useful supervillains into his Senior Citizombies, using their talents to spread the infection as fast as possible until nearly all life on Earth is reshaped to Grandfather's whims. Planning to destroy the Book of KND so no hope can survive amidst children, Grandfather is so fierce that he terrifies his villainous son Father, defeats his other boy Monty in combat, and survives the KND space headquarters crashing into him, even facing defeat with just a snark to Monty that he's no longer in the will.
• 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. Not to mention that the transformation is from her point of view.
• 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.
  • Though the scene was funny, many fans were disappointed that Father ultimately decided not to help Numbuh Zero fight Grandfather in the climax. Not only would it have been an epic Enemy Mine moment, but it could've been a good way to remind viewers how dangerous Father was before his Villain Decay.

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