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