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