Early concept art of the show in its earliest stages, with Libby being absent and an unknown basketball player (possibly an early concept for Nick).
Film
- The film originally acted as the pilot episode
(titled Runaway Rocketboy) for what would eventually become The Adventures of Jimmy Neutron, Boy Genius. As mentioned on the film's main page, Nickelodeon was so impressed with the pilot, that they funded a whole feature-length film based on it. In a sense, the film itself acts as the pilot for the animated series. Not many cartoonists can brag about something like that, you know. - Sheen was intended to be Japanese and had originally been named "Shin", but after the filmmakers were unable to find a suitable voice actor of Japanese descent for the role, they decided instead to make the character Hispanic and settled on Mexican-American stand-up comedian Jeffrey Garcia to provide his voice.
- Not only was Libby a last-minute inclusion, but she also looked very different at one point◊.
- The original script for Runaway Rocketboy was planned as an independent live-action short, but John A. Davis could only get funding for it if it was educational. He dug out the script a few years later when his company DNA Productions was getting started.
- Kevin Michael Richardson was going to voice Captain Spoor, where they retrieve the toaster. The footage can be found in the trailer.
- If you go through every pre-release media (possibly including trailers), you'll notice that they are from an earlier version of the film.
- The most notable is the fact that Jimmy and his friends were all going to go to Retroville and rescue their parents in separate rockets, rather than just Jimmy and Carl.
- Plans for a sequel to the film titled Jimmy Neutron 2: The Search for Carl were made with plans to release in the summer of 2004. While the sequel itself was scrapped, the story did go on to be the basis for the GBA version of the game Jimmy Neutron vs. Jimmy Negatron. According to Keith Alcorn (the co-creator of DNA Productions), the movie was ultimately cancelled because it seemed redundant to create another film after the popularity of the TV show.
TV Series
- The earliest pilot animation was going to be called The Adventures of Johnny Quasar. A test animation was created, but not much else came from it. Early designs were very different from the final such as Jimmy's parents◊ and friends◊, (with an unknown character holding a basketball, possibly an early concept for Nick) but not Goddard, much◊. In the short, the neutron logo was a "Q" design instead of an atom design. When Nickelodeon picked it up, they requested the character's name be changed to avoid confusion with Jonny Quest.
- Johnny Quasar was also originally intended to be a fully live-action short in the 1980s, but years in Development Hell turned it into an All-CGI Cartoon.
- The main theme was slightly longer with a couple more lyrics.
- According to the show's page on The Other Wiki, there was going to be a fourth season, which would've been Darker and Edgier. First, the season premiere episode "Deep Impacts" would've shown Jimmy's Final Battle with Evil Jimmy. Another episode would feature Cindy and Betty interacting with each other, Cindy and Jimmy would've finally become a couple, and Nick, who was basically Demoted to Extra in the show, would've gotten a larger role. Finally, there were going to be more appearances from the League of Villains. The fourth season was scrapped after DNA Productions went out of business following the commercial failure of their film The Ant Bully and many of the staff team at O Entertainment moving on to work on Barnyard and its television adaptation.
Planet Sheen
- There was going to be an Ultra Lord spinoff◊, but it was scrapped in favor of this show.
- This show was a Dolled-Up Installment. It was originally going to be called Red Acres and feature a dumb fast food restaurant worker getting launched into space and eventually crash-landed on a planet inhabited by dimwitted hillbilly aliens who mistakes him for a genius. Nickelodeon didn't normally do shows about adult protagonists, so they retooled it as a Jimmy Neutron spin-off.
- The show was originally going to be more serious. The Emperor was evil, Aseefa was the leader of a resistance group, and Sheen was a double agent working for both sides. This was changed because it was too close to the 2009 blockbuster Avatar.
- Carl was originally going to also be part of the show alongside Sheen, but due to Executive Meddling, he was instead replaced with Doppy Dopweiler.
- There was going to be a TV movie about Jimmy and the gang going to rescue Sheen, but due to low ratings, production costs and several writers moving on, it was cancelled.
