• Adaptation Displacement: While The Movie was very popular, and still pops up on Nick every now and again, people often forget about it.
  • Complete Monster: Meldar from the Win, Lose and Kaboom special, who makes a game show out of destroying planets and committing mass genocide.
  • Critical Research Failure (Happens pretty much all the time, surprisingly. Jimmy stating that Australia isn't a continent[it is], calling the Cretaceous period the Cretaceous era [the terms aren't interchangeable, and it was the wrong period to begin with], saying that Thomas Edison invented electricity [electricity existed beforehand], stating that Chinese ginseng is a muscle relaxant [it isn't], and that a person can never change because their personality is imprinted on their brain at birth [safe to say, it's not.])
  • Fan Disservice: Jimmy is seen in his boxers for a few minutes in The Movie, and in several instances of the TV show (and even completely naked in one episode!). Meanwhile, Cindy's panties are shown only in the first episode.
  • Growing the Beard (More of like Braiding the Hair; episodes after "Beach Party Mummy" tend to stand out more, shedding the spin-off-of-the-movie feel. In that particular episode Libby has decided to keep her hair braided, making her stand out more as well.)
  • Hilarious in Hindsight (In Retroville 9 Jimmy creates high-tech baseball gloves and automatic homerun hitting bats neutronized with the skills of three baseball players for his struggling baseball team. They effectively cheat their way to the little-league finals in Japan. The players Jimmy used were Barry Bonds (an alleged cheater), Mark Mc Gwire (a confessed cheater) and Babe Ruth.
  • The Masochism Tango (Jimmy and Cindy)
  • Nightmare Fuel: Does anyone remember the episode when Evil Jimmy tricks Jimmy into thinking he's good, and creates a new world that's sapping reality from earth? Jimmy proceeds to reverse the process, killing every one of the billions of evil humans. He killed an entire species. That's xenocide.
    • The entire "One of Us" episode. Creepy as it was, it was the ENDING that had me run to make this entry. As the grandmother boards the mothership, it seems like the episode will only end on a peculiar "WTF" note. Instead, she turns around, lifts her glasses to reveal completely black eyes, and says "WE'LL BE BACK." in a terrifyingly deep voice. Still shaken, and it's been about ten minutes.
    • The giant spider in "Stranded!"
    • The Nanobots proceeding to delete everyone from existence due to them being "flawed". If Jimmy hadn't intervened before they hit the "empty recycle bin" option...
    • "Sheen's Brain" where Sheen's head eventually gets so big it takes over his body.
  • Shipping (Lord Almighty. Don't even get me started. Fangirls are INSANE.)
  • They Wasted a Perfectly Good Plot: For Jimmy/Timmy Power Hour 3, which was originally was supposed to be a Grand Finale for both shows. Who didn't want to see a 3D Dimmsdale and a 2D Retroville, and see Crocker spazzing out in 3D?
  • Uncanny Valley: Some aspects of the CGI have not aged well.