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