Completed Mission 6 as Contractor or higher.

Unlocked: 29 May 2008 03:32:44

Kill 50 enemies total in Back-to-Back.

Unlocked: 29 May 2008 03:19:24

Completed Mission 5 as Contractor or higher.

Unlocked: 29 May 2008 01:14:08

Purchase 3 weapons.

Unlocked: 29 May 2008 00:01:55

Completed Mission 4 as Contractor or higher.

Unlocked: 27 May 2008 20:35:56

Kill 250 enemies total using Assault Rifles.

Unlocked: 27 May 2008 20:30:32

Drag and heal your partner 25 times.

Unlocked: 27 May 2008 19:47:41

Completed Mission 3 as Contractor or higher.

Unlocked: 27 May 2008 19:18:57

Spend 1 minute straight at full Aggro.

Unlocked: 27 May 2008 18:37:15

Completed Mission 2 as Contractor or higher.

Unlocked: 25 Apr 2008 01:09:46

Completed Mission 1 as Contractor or higher.

Unlocked: 24 Apr 2008 23:13:46

Heal your partner for the first time. Training does not count.

Unlocked: 24 Apr 2008 23:07:32

Complete all missions as a Professional.

Complete all missions with the Partner AI.

Purchase the MP7, M134, DAO-X Protecta, MGL MK-X, and the M107 Light Fifty.

Purchase every mask variant.

Earn one million dollars in total over the course of campaign mode.

Kill 50 enemies total in Co-op Riot Shield.

Kill 5 enemies total using Co-op Snipe.

Kill 250 enemies total using Shotguns.

Kill 250 enemies total using Machine Guns.

Kill 150 enemies total using Handguns.

Kill 250 enemies total using SMGs.

Kill 100 enemies total using Sniper Rifles.

Kill 25 enemies total using RPGs.

Kill 50 enemies total using the Melee Attack.

Kill 25 Martyrs by shooting the Bomb Packs on their chests.

Kill 25 Heavy Armor enemies.

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.

Kill 100 enemies while in the power mode of Overkill.

Kill 30 enemies using the Riot Shield melee attack

Collect all of the information cases in the entire game.

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

Completed Mission 7 as Professional.

Completed Mission 8 as Professional.

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