Highlight the microphone on the left side of the main menu in the campaign. Press
the Right Mouse Button, then type "idaho". A new drop down menu that allows any
level to be selected will appear at the top right of the screen.
To be invincible Type "I am the ace" at the
loading screen after the briefing you will be
invincible for that mission, you have to type
this code in the begining of each new mission.