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