Cheat mode:

Select the "Top Secret" option at the main menu. Enter one of the following codes, represented by the Numbuh of the kids.

Invincibility:

Enter 432513 as a code

Hint: Yatta Yatta Yatta: Super Secret:

If your playing Numbuh 5, you get through the stage Yatta Yatta Yatta. Get to the part with the disco ball. Note: When you step under the disco light, robots appear. There is a Super Secret to be found. When you first get the intermission sequence, you see you are entirely surrounded. Near the left in the far distance should be a pool table. Go over to it. Once there, notice the pool balls on the table. Use your character to push the balls into the nearby fireplace. Once you get one in, you should hear the same sound that plays when you get a rainbow monkey. Keep track of all the pool balls. If you lose one and cannot find it, you cannot get the Super Secret. When you get all the pool balls in the fireplace, a strange icon drops from it. Run into it and you should get a Super Secret unlocked message.