The novelization is clearly based on an early draft of the screenplay, as it includes Captain Spoor and a few additional scenes that were cut from the movie.
A toy rocket comes with a figure of Jimmy wearing a striped shirt, much like what he wore in the Runaway Rocket Boy pilot. The commercial for said toy even used clips from the pilot.
Keep Circulating the Tapes: On May 19th, 2007 Nickelodeon premiered a TV Special called GENIUS, SHEENIUS, OR INBETWEENIUS. This special was the movie with in-character commentary done by the silhouettes of Jimmy, Carl, and Sheen in the style of Mystery Science Theater 3000 (It was also the last time Debi Derryberry would voice Jimmy in the show, as the series had ended by that point, so it was a Bookend in a way as well). It aired with quite a bit of promotional advertising and fanfare, but was never shown again, and couldn't even be found online until recently.
Kids' Meal Toy: In Australia, Red Rooster had figures of Jimmy, Carl, Cindy, Goddard, and King Goobot in their Kids' Meals.
Pretty much everything in the teaser. Justified, as a lot of it is very early test footage. Most of the scenes got recycled for smaller shorts that premiered during commercial breaks on Nickelodeon around the time the film was in post-production.
The theatrical trailer had a scene with a group of Yokians, with Captain Spoor voiced by Kevin Michael Richardson.
In the same trailer, Cindy says, "If we blow up, whatever's left of me is kicking your butt".
Working Title: It started as a movie script called Runaway Rocketboy which was used for the pilot episode of the TV series. The character was originally supposed to be called "Johnny Quasar" and debuted in an animated short of the same name but was renamed due to it sounding to similar to Jonny Quest.
Acting for Two: Rob Paulsen voices Carl, all of the Yokians, and all of the Retroland workers in the game.
Easter Egg: One sound clip in the game files sounds like a brief segment from Carmina Burana, followed by some loud, high-pitched, and mostly incomprehensible noises that vaguely resemble speech. If you slow it down 50% and listen carefully, it's somewhat discernible. Here's a guess at what might be said:
Voice 1: "(Conti)nue the search. Please target the house and retrieve them there with the small wooden objects."
Voice 2: "Order our flank and to target that building and teleport him to me, at once!"
Whether this is an actual Easter Egg, an error in exporting the sound from the game files, or merely the developers being silly is unknown.
What Could Have Been: This pre-release screenshot◊ looks very different from the released version. Most notable are Jimmy's different appearance, Goddard having his own neutron energy meter, a Yokian guard and ship roaming the school grounds, and the school grounds laid out differently.