To make the missions extra hard and to start with some medals type in INVALIDCODE you will the be taken to the level where you destroy the train. As normal finish the campain to choose the other missions.
(0=zero, o=letter o)
(1=one, I=letter I)
South America
Level 1-oNHV0V6VEBDU55Q
Level 2-2NH70V9VEFDQ592
Level 3-7RH30V7AEFD64BI
Level 4-8NH30V8EEJD24PI