Here is the full list of all 66 Alien Swarm achievements.
Complete a campaign on Normal difficulty or harder without any marines dying.
Complete the Jacob's Rest campaign on Hard difficulty or harder.
Awarded for finishing the Jacob campaign on Insane difficulty.
Awarded for finishing the Jacob campaign on Brutal difficulty.
Complete 10 computer hacks without access being logged.
Heal 300 points of damage in a single mission without dealing any non-melee damage to the Swarm.
Complete any mission on Brutal difficulty with Onslaught and Hardcore Friendly Fire enabled.
Complete Timor Station within 4:25 on Normal difficulty or harder without any marines dying.
Complete SynTek Residential within 2:30 on Normal difficulty or harder without any marines dying.
Complete Sewer Junction within 1:30 on Normal difficulty or harder without any marines dying.
Complete Rydberg Reactor within 3:10 on Normal difficulty or harder without any marines dying.
Complete Deima Surface Bridge within 2:30 on Normal difficulty or harder without any marines dying.
Complete Cargo Elevator within 2:50 on Normal difficulty or harder without any marines dying.
Complete Landing Bay within 1:25 on Normal difficulty or harder without any marines dying.
Complete the Jacob's Rest campaign on Normal difficulty or harder.
Complete the Jacob's Rest campaign on Easy difficulty or harder.
Complete a mission with no friendly fire incidents. Four marines must be present in the mission.
Destroy all Swarm Eggs in a mission without allowing any to hatch.
Kill 100 Swarm Grubs.
Kill 100 Swarm with Incendiary Mines.
Kill 100 Swarm with Laser Tripmines.
Kill 250 Swarm with a Grenade Launcher.
Unlock all the available weapons.
Kill a Swarm Parasite with a melee attack.
Complete 10 wire hacks without access being logged.
Kill 100,000 Swarm.
Kill 25,000 Swarm.
Kill 250 Swarm with a Tesla Cannon.
Kill 250 Swarm with a Marksman Rifle.
Kill 250 Swarm with a Chainsaw.
Kill 5,000 Swarm.
Kill 250 Swarm with a Minigun.
Kill 250 Swarm with PDWs.
Deploy 10 ammo stashes that are used by other marines.
Kill 500 Swarm with deployable Sentry Guns.
Kill 250 Swarm with a Flamethrower.
Kill 15 Swarm with all four marines under the effects of a Damage Amp in a single mission.
Freeze 6 Swarm with a single Freeze Grenade.
Kill 6 Swarm with a single Grenade.
Cure an Infested marine.
Kill 5 Swarm with explosive barrels in a single mission.
Kill a Swarm Boomer before it inflates.
Heal all 4 marines with a single Heal Beacon.
Complete a mission with better than 90% accuracy.
Kill 250 Swarm with a Rail Rifle.
Kill 250 Swarm with a Shotgun.
Kill 250 Swarm with Twin Pistols.
Kill 100 Swarm with Hornet Barrages.
Complete a mission on Normal difficulty or harder without any marines dying.
Deliver the finishing blow to a Swarm Shieldbug.
Kill 20 Swarm with melee attacks in a single mission.
Kill 250 Swarm with a Vindicator.
Kill 250 Swarm with an Autogun.
Kill 250 Swarm with a Prototype Rifle.
Kill 1,000 Swarm.
Kill 25 drones without friendly fire. Four marines must be present in the mission.
Complete a mission on Normal difficulty or harder without receiving any damage.
Successfully perform 5 fast reloads in a row.
Successfully perform a fast reload.
Guard the squad's tech so that he takes no damage during the hack.
Finish a mission without the tech getting killed.
Stun 6 Swarm with a single Stun Grenade.
Seal a door with the welder.
Roll under a Swarm Ranger projectile.
Kill 250 Swarm with the Assault Rifle.
Complete 2 co-op missions online. Earns a Team Fortress 2 parasite hat.