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