To play as a fire fighter or policeman, complete the stages "Outbreak" and "Hell Fire" with any charter. Once done, go to the "Collection" option at the main menu and choose "Costumes". Both of those costumes cost 5,000 points. After unlocking them, they can be used on any stage. Note: They are Kevin and Mark's other costumes. When playing as either a fire fighter or policeman, they will have Kevin and Mark's storylines and voice effects.