Using codes sooner
Start a single player game. In the first world when you are able to use Mumbo Jumbo, control the Golden Goliath and lead him to the huge doors near the entrance of the world. Kick the doors open. Make a left in "Jade Snake Grove" then make a left into the muck. Collect the Jiggy that is there, and continue to the right. You will find an area with two dart spitting enemies. Walk of the temple that they are protecting and kick the door. That is the "Code Chamber" where you can enter Cheato's codes.