To activate the following passwords enter them at the 'Secrets' menu. Some codes require you to be at a certain level before they have an effect.
Easier Game: Enter THISISTOOHARD as a password.
Harder Game: Enter THISISTOOEASY as a password.
Unlock Level Select: Enter LEVELLOCKSMITH as a password
Unlock Infinite Energy: Enter WHYMUSTWEFIGHT as a password
Unlock Frozone's Super Move: Enter FROZBOOM as a password
Frozone has Everything at Max: Enter FROZMASTER as a password
Frozone Gets 1,000 Experience Points: Enter FROZPROF as a password
Mr. Incredible Gets 1,000 Experience Points: Enter MRIPROF as a password
Unlock Mr. Incredible's Super Move: Enter MRIBOOM as a password
Mr. Incredible has Everything at Max: Enter MRIMASTER as a password
Mr. Incredible and Frozone Move Faster: Enter INAHURRY as a password
Disable HUD: Enter HUDBEGONE as a password
Unlock Full Gallery: Enter SHOWME as a password
View Credits: Enter ROLLCALL as a password
Get the Gallery Item in Underminer Threat: To find the Gallery Item in Underminer Threat go to the third gate that you can break and then go backwards until you see a black wall on the left that has cracks in it. When you Break this black wall you will be able to get the item.