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