Full list of all 65 Left 4 Dead 2 achievements worth 1,500 gamerscore. It takes around 20-25 hours to unlock all of the achievements in the base game.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 2 DLC packs containing 15 achievements worth 500 Gamerscore.
Survive the Swamp Fever campaign.
Survive the Hard Rain campaign.
Finish a campaign using only melee weapons.
Kill one of each Uncommon Infected.
Kill 10 swampy Mudmen while they are in the water.
Honk the noses of 10 Clowns.
Prove you are faster than Moustachio.
Prove you are stronger than Moustachio.
Rescue Gnome Chompski from the Carnival.
Defend yourself at the crashed airliner without taking damage.
Navigate the sugar mill and reach the safe room without killing any Witches.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Cross the bridge finale in less than three minutes.
Survive all campaigns on Expert.
Survive a campaign on Expert skill with Realism mode enabled.
Kill a Charger with a melee weapon while they are charging.
Stop the enemy team from collecting any gas cans during a Scavenge round.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Revive 10 dead Survivors with the defibrillator.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
As the Charger, bowl through the entire enemy team in a single charge.
Kill a Tank with melee weapons.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
Collect 100 gas cans in Scavenge.
Cause 25 gas can drops as a Special Infected.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
As the Jockey, ride the Survivors twice in a single life.
In a Survival round, get a medal only using melee weapons.
As the Spitter, hit every Survivor with a single acid patch.
As the Spitter, spit on a Survivor being choked by a Smoker.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
As the Charger, grab a Survivor and carry them over 80 feet.
As the Jockey, ride a Survivor for more than 12 seconds.
Collect 15 gas cans in a single Scavenge round.
Make a Survivor drop a gas can during overtime.
Win a game of Scavenge.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Ignite 50 Common Infected with incendiary ammo.
Survive the Parish campaign.
Kill 100 Common Infected with the chainsaw.
Use every melee weapon to kill Common Infected.
Survive the Dark Carnival campaign.
Decapitate 200 Infected with a melee weapon.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Survive the Dead Center campaign.
Use a bile bomb on a Tank.
Deploy an ammo upgrade and have your team use it.
Kill a Spitter before she is able to spit.
Kill 15 Infected with a single grenade launcher blast.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Play 5 full games of Scavenge on The Port.
Play 6 Mutations.
Using the M60, kill 25 infected without letting go of the trigger.
Open 5 foot lockers.
Collect 10 items dropped by a Fallen Survivor.
Survive The Passing Campaign.
Kill a Tank only with damage from the original Survivors.
Play the new Midnight Riders song on a jukebox.
Knock off the heads of 18 infected with the golf club.
Have all 3 generators running at once in "The Sacrifice" finale.
As a Special Infected, incap someone who is trying to sacrifice themselves.
Kill a Special Infected with an exploding barrel.
Have Bill sacrifice himself for the team.
Complete "The Sacrifice".