Instructions
Complete the game once without killing a single enemy. Many enemies can be avoided without a confrontation, or you can knock them out with tranquilizer darts or through non-lethal physical combat. This will unlock the Bandana for free.
Collect five million "Drebin points" during your game. These points can be obtained through defeating enemies, with extra points being awarded for non-lethal takedowns. "Gecko's" give you 5,000 points each.
Use these five millions "Drebin points" to purchase the Bandana from Drebin after defeating the game. The Bandana will only be available for purchase after defeating the game under any difficulty setting.