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