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