Shake the game to display the "Enter Cheat Code" screen. Enter one of the following codes to activate the corresponding cheat function.

All extra rewards
Enter pay tribute to your king as a code.

Construction costs set to $0
Enter i am weak as a code.

High tech industries
Enter nerdz rule as a code.

Recycling plant, waste to energy incinerator and normal incinerator
Enter garbage in, garbage out as a code.