Operation Quarterback 10 Completed Act 1 Operation Archangel 20 Completed Act 2 Left No Man Behind 20 Completed the game on Casual My Rifle Is My Best Friend 50 Completed the game on Medium Harvester Of Sorrow 75 Completed the game on Expert Poking the Bush 20 Collected all secrets in Act 1 Keepsakes Of War 20 Collected all secrets in Act 2 In Search of Enlightenment 20 Collected all secrets in Act 3 Hazardous Materials 25 Killed three or more enemies by shooting a grenade Death's Scythe 30 Took 50 headshots in single player Nerves Of Steel 30 Achieved 100% accuracy in any single player mission ***** Of Steel 20 Completed any single player mission without using med kits, but taking damage Say Hello To My Little Friend 10 Killed 30 enemies using your sidearm Psst, Don't Look Behind You 20 Killed 15 enemies with a stealth kill Kill With Still 10 Killed 50 enemies while holding your breath Distance Matters Not 20 Killed 20 enemies from a distance of 600m or greater Fisher King 10 Killed 25 enemies using thermal or night vision goggles Worlds Apart 20 Took a successful shot from a distance of 1 km or greater Bullets Can't Hurt Me 25 Completed any act without using medkits I Never Bleed 75 Completed the Campaign using max one medkit per mission Bloodstreak 10 Killed 25 opponents in multiplayer Pure Ownage 30 Killed 50 opponents in multiplayer The Sniper Elite 50 Killed 100 opponents in multiplayer Kill That F**ing Band! 20 Took 25 headshots in multiplayer Blood And Tears 50 Took 50 headshots in multiplayer Unhappy Camper 10 Killed 10 opponents in multiplayer using your sidearm U Can't Touch This 50 Won 5 rounds in a row in Team Deathmatch Wrath Child 10 Won 10 Team Deathmatch rounds Death Dealer 30 Won 25 Team Deathmatch rounds Everything But The Kitchen Sink 50 In one multiplayer round killed an opponent with a sniper rifle, sidearm and melee attack World Warrior 5 Participated in any multiplayer match Secret Achievements Secret Achievement 10 Continue playing to unlock this secret achievement. Secret Achievement 10 Continue playing to unlock this secret achievement. Secret Achievement 50 Continue playing to unlock this secret achievement. Secret Achievement 30 Continue playing to unlock this secret achievement. Secret Achievement 15 Continue playing to unlock this secret achievement. Secret Achievement 20 Continue playing to unlock this secret achievement. Secret Achievement 20 Continue playing to unlock this secret achievement. Source - X360A