Cheat Mode is an option found in the game settings on the "Continue Game" or "Start New Game" screen and can be found under the "Misc" tab. This allows you to have access to the Creative Menu in the game. Once enabled, you can use and place any item from the Creative Menu.
To open the Creative Menu, press the U key.
To enable/disable God mode, press the Q key.
To enable/disable Flying, press the H key. While flying, press Space to go up and C to go down. Fly faster by pressing and holding Shift.