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