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