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