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