Continuity mistake: When Jimmy Neutron is giving birthday presents to his mum he pulls out a necklace and some earrings from a bag. His mum only takes the necklace from him but the earrings are no longer in his hand. (00:20:10)
Continuity mistake: When Jimmy and the rest of the kids are standing on the balcony, Jimmy asks Goddard to activate his binoscope so they can get a better view of the arena. Goddard then extends his eyes into tubes and raises them. However, in the next shot, his eyes are raised but not extended into tubes yet. They also take on a different shape than in the previous shot. (01:04:53)
Other mistake: When the kids are standing on the balcony after escaping from the dungeon, the arena is shown in the distance. Jimmy asks Goddard to activate his binoscope to get a look at their parents in the arena. The problem is that the walls of the arena obscure the center where the parents are dancing, which means that Goddard wouldn't have been able to get a clear view without going to a higher level. (01:04:55)
Continuity mistake: Nick's necklace is a string looped through a ring, but sometimes the string makes only one pass through the ring and sometimes two.
Character mistake: When Jimmy explains to the kids of the town where the aliens took their parents, he mentions the origin of the aliens being somewhere in the Orion Star System, 3 million light years away. The Orion system is way closer than that. It is actually less than 1400 light years away from Earth. 3 million light years away would place them further than the Andromeda Galaxy.
Suggested correction: This shouldn't be a character mistake. A genius like Jimmy would know something like this. It's basic astronomy.
That's exactly why it's a character mistake. A character mistake is when a character does or says something that they shouldn't based on who/what they are suppose to be, or something a character wrongly states as fact when they should know better.
Continuity mistake: In the opening sequence, Jimmy uses a long string from Carl's shirt to help launch the satellite. Jimmy then launches Carl from the rocket. That same morning, Jimmy finds Carl hanging from a tree, and his shirt is intact.
Plot hole: When the aliens kidnap the adults, the kids are left behind. But all the kids seen are around 11 and younger. Where are the teenagers or young adults? None of them are during the celebration scene nor in the arena on the alien planet.
Factual error: When Cindy is giving her "fossil-to-chromosome ratio" report, she calls her model dinosaur skeleton a plesiosaur. However, the skeleton is of a bipedal dinosaur (likely a hadrosaur, judging by the "duckbill"), while plesiosaurs were aquatic reptiles with flippers instead of feet.
Plot hole: At the beginning of the movie, Jimmy's rocket could barely stay in one piece, much less leave the atmosphere. And that was only one rocket. But later on, not only can he build a much better rocket from one of the rides in the amusement park, but he can build ones for the other kids as well. It's not like he got better at building rockets, he tried to build another one in his yard before he and the town's kids did, but it fell apart.
Continuity mistake: When Jimmy goes to check his experiments, there is a fish tank type thing and he then checks the invisible hamsters and the girl eating plant, but when he gets to the burping soda the fish tank thing is gone.
Plot hole: Jimmy enacts a ploy to make Ooblar think Goddard will self-destruct in a massive explosion. Ooblar runs out of the lab where Goddard escapes and frees Jimmy and the kids from the dungeon. Shouldn't have Ooblar realised something was up when no explosion occurred and went back to see the dog and the kids have escaped and sounded the alarm, especially to King Goobot? Yet the Yolkians are shocked when they see the kids in the arena later, meaning Goobot was not informed about it prior by Ooblar.
Plot hole: When Jimmy is piloting the Yolkian cargo ship, while being chased by the Yolkian Armada, he steps on a pedal as he flies the ship around a star to escape the chasing ships. The vessel he is piloting was built and designed by a race of aliens who don't have solid bodies and use hovering pods to move around. There is no reason the ship should have pedals or pedals placed in any way that would require the pilot to have legs.
Continuity mistake: During the show and tell scene, when Cindy finishes her presentation, she carries her model dinosaur skeleton back to her desk. However, the dinosaur skeleton is not seen at her desk, nor is it with her when the students leave after the dismissal bell.
Other mistake: The size of the town Jimmy lives in is inconsistent with the size of the population shown. The town is quite big if it has its own mall, amusement park, and a large elementary school. Yet combined with the kids and adults seen, there couldn't be more than a hundred people living in this town.
