Drag and heal your partner 25 times.
Collect all of the information cases in the entire game.
Kill 100 enemies while in the power mode of Overkill.
Earn one million dollars in total over the course of campaign mode.
Kill 25 enemies total using RPGs.
Kill 25 Martyrs by shooting the Bomb Packs on their chests.
Complete all missions as a Professional.
Kill 30 enemies using the Riot Shield melee attack
Kill 250 enemies total using Machine Guns.
Kill 250 enemies total using Shotguns.
Purchase the MP7, M134, DAO-X Protecta, MGL MK-X, and the M107 Light Fifty.
Kill 100 enemies total using Sniper Rifles.
Kill 250 enemies total using SMGs.
Kill 25 Heavy Armor enemies.
Kill 150 enemies total using Handguns.
Purchase 3 weapons.
Continue playing to unlock this secret achievement.
Purchase every mask variant.
Kill 250 enemies total using Assault Rifles.
Kill 50 enemies total using the Melee Attack.
Kill 50 enemies total in Back-to-Back.
Spend 1 minute straight at full Aggro.
Heal your partner for the first time. Training does not count.
Complete all missions with the Partner AI.
Kill 50 enemies total in Co-op Riot Shield.
Kill 5 enemies total using Co-op Snipe.
Finish playing a versus ranked match.
Complete 20 minor objectives in a ranked match.
Complete a ranked match without ever needing to be revived.
Earn one billion dollars in total in ranked matches.
Win a ranked match without purchasing any additional weapons.
Kill 75 enemies while in the stealth mode of Overkill.
Win every stage of a ranked three round SSC Challenge match
Destroy 500 barrels in ranked SSC Challenge matches
Win a ranked SSC Challenge match
Achieve 75% accuracy at the conclusion of a ranked three round SSC Challenge match
Buy the 'pack 8' gun pack in a multiplayer ranked match
Destroy 300 destructible objects in Mission 7,8
Kill Dalton in less than 40 seconds
Final blow to Dalton is a headshot with a pimped .44 MODEL 29 handgun