Jimmy Neutron vs. Jimmy Negatron Cheats & Codes

Unlock More Levels

To use these codes, go to the main menu. When you see a blue neutron on Jimmy's computer, press down. Jimmy will say in a speech bubble "Can I continue a game?" Press A to bring up a code screen. All circled letters are presented as "(B)"
Power Plant, My Computer, and Caves

Quantum Dimension, Jelly Dimension, Rocket Launch Site

Retroland and Jimmy Negatron
Each codes unlock the level that the code mentions with a full bar of life and a full bar of ammo.

Jimmy Neutron vs. Jimmy Negatron Hints, Tips, Tricks, Secrets, & Glitches

Cindy's Dream

To not get hit by the butterflies while standing, use Goddored. He is shorter and won't get hit by them. But you still have to watch out for the butterflies when you jump.