Within the game's data are unused splash screens for almost every level, with the exceptions being "Neighborhood Nightmares", "Rollercoaster Boss", and "Final Boss". Of note is that the splash screen for "Bat Outta Heck" uses a placeholder graphic, featuring the screen for "Sideshow Spectacular" with "BAT Outta Heck Loading" written on top in Comic Sans. In the final game, every level uses the same generic loading screen depicting the Jimmy Neutron logo and an animation of one of the atoms from the original TV show's opening, with the only differences being the level names themselves.

An Xbox version was planned at some point, but was cancelled for unknown reasons.

Unused code for the "Scribble HUD," "Super Power Recharge," and "Thermographic Spectrafier" can be found in the GameCube and PlayStation 2 version's files, suggesting these may have been planned to be power ups.