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