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