From StrategyWiki, the free strategy guide and walkthrough wiki

There are 37 achievements in Army of Two worth a total of 1000 .

Picture	Achievement	Description
	Elite PMC	Complete all missions as a Professional.	50
	My Virtual Friend	Complete all missions with the Partner AI.	35
	Say Hello to my Little Friends	Purchase the MP7, M134, DAO-X Protecta, MGL MK-X, and the M107 Light Fifty.	45
	Man of Many Masks	Purchase every mask variant.	50
	If I Were a Rich Man	Earn one million dollars in total over the course of campaign mode.	40
	Fear is The Mind Killer	Spend 1 minute straight at full Aggro.	45
	Starting a Riot	Kill 50 enemies total in Co-op Riot Shield.	30
	Two Eyes are Better Than One	Kill 5 enemies total using Co-op Snipe.	35
	Seven-six-two Millimeter	Kill 250 enemies total using Assault Rifles.	20
	This is my Boom Stick!	Kill 250 enemies total using Shotguns.	20
	Spray and Pray	Kill 250 enemies total using Machine Guns.	20
	Dead Man's Hand	Kill 150 enemies total using Handguns.	20
	Alright, Who Wants Some?	Kill 250 enemies total using SMGs.	20
	One Shot. One Kill.	Kill 100 enemies total using Sniper Rifles.	20
	Big Boom! Big Bada Boom!	Kill 25 enemies total using RPGs.	20
	Flip You. Flip You For Real	Kill 50 enemies total using the Melee Attack.	20
	Fission Mailed	Kill 25 Martyrs by shooting the Bomb Packs on their chests.	20
	If It Bleeds, We Can Kill It	Kill 25 Heavy Armor enemies.	30
	Field Medic	Drag and heal your partner 25 times.	30
	Boots on the Ground	Finish playing a versus ranked match.	10
	The Devil's in the Details	Complete 20 minor objectives in a ranked match.	20
	Surviving The Game	Complete a ranked match without ever needing to be revived.	25
	Retirement Savings Plan	Earn one billion dollars in total in ranked matches.	40
	Out of Debt	Heal your partner for the first time. Training does not count.	15
	One Gun is Enough	Win a ranked match without purchasing any additional weapons.	35
	Beast with Two Fronts	Kill 50 enemies total in Back-to-Back.	20
	Running Man	Kill 75 enemies while in the stealth mode of Overkill.	30
	L'Abattoir	Kill 100 enemies while in the power mode of Overkill.	30
	Weapon Specialist	Purchase 3 weapons.	15
	Stonewall	Kill 30 enemies using the Riot Shield melee attack	30
	My Kind of Case!	Collect all of the information cases in the entire game.	40

[edit] Secret

Picture	Achievement	Description
	Mission 1 Complete	Completed Mission 1 as Contractor or higher.	30
	Mission 2 Complete	Completed Mission 2 as Contractor or higher.	30
	Mission 3 Complete	Completed Mission 3 as Contractor or higher.	15
	Mission 4 Complete	Completed Mission 4 as Contractor or higher.	15
	Mission 5 Complete	Completed Mission 5 as Contractor or higher.	15
	Mission 6 Complete	Completed Mission 6 as Contractor or higher.	15