Full list of all 101 Left 4 Dead 2 achievements. It takes around 80-100 hours to unlock all of the achievements in the base game on Windows.
The base game contains 52 achievements, and there are 7 DLC packs containing 49 achievements.
Collect 100 gas cans in Scavenge.
Make a Survivor drop a gas can during overtime.
Kill 15 Infected with a single grenade launcher blast.
Prove you are faster than Moustachio.
Prove you are stronger than Moustachio.
As the Charger, bowl through the entire enemy team in a single charge.
Finish a campaign using only melee weapons.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
Kill a Charger with a melee weapon while they are charging.
As the Spitter, spit on a Survivor being choked by a Smoker.
As the Charger, grab a Survivor and carry them over 80 feet.
Revive 10 dead Survivors with the defibrillator.
As the Spitter, hit every Survivor with a single acid patch.
Kill a Tank with melee weapons.
Win a game of Scavenge.
As the Jockey, ride the Survivors twice in a single life.
Stop the enemy team from collecting any gas cans during a Scavenge round.
Collect 15 gas cans in a single Scavenge round.
Cross the bridge finale in less than three minutes.
Survive a campaign on Expert skill with Realism mode enabled.
Survive all campaigns on Expert.
Navigate the sugar mill and reach the safe room without killing any Witches.
Kill 10 swampy Mudmen while they are in the water.
Defend yourself at the crashed airliner without taking damage.
Honk the noses of 10 Clowns.
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.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Rescue Gnome Chompski from the Carnival.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
As the Jockey, ride a Survivor for more than 12 seconds.
Ignite 50 Common Infected with incendiary ammo.
Decapitate 200 Infected with a melee weapon.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Deploy an ammo upgrade and have your team use it.
Survive the Hard Rain campaign.
Survive the Parish campaign.
Survive the Swamp Fever campaign.
Survive the Dead Center campaign.
Use every melee weapon to kill Common Infected.
Survive the Dark Carnival campaign.
Kill 100 Common Infected with the chainsaw.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Kill one of each Uncommon Infected.
Kill a Spitter before she is able to spit.
Use a bile bomb on a Tank.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
In a Survival round, get a medal only using melee weapons.
Cause 25 gas can drops as a Special Infected.
Plays games with free weekend players and helps them survive a campaign.
Spread cheer by helping a free holiday player survive a campaign.
Kill a Tank only with damage from the original Survivors.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Play 6 Mutations.
Collect 10 items dropped by a Fallen Survivor.
Open 5 foot lockers.
Using the M60, kill 25 infected without letting go of the trigger.
Survive The Passing Campaign.
Knock off the heads of 18 infected with the golf club.
Play the new Midnight Riders song on a jukebox.
Play 5 full games of Scavenge on The Port.
Have Bill sacrifice himself for the team.
Have all 3 generators running at once in "The Sacrifice" finale.
Complete "The Sacrifice".
Kill a Special Infected with an exploding barrel.
As a Special Infected, incap someone who is trying to sacrifice themselves.
Survive the Cold Stream campaign on any difficulty.
Play a Versus game on Dead Air from start to finish.
Collect three gifts dropped by Special Infected in Versus Mode.
Instantly kill a Survivor as the Charger.
On the concert finale, survive until the helicopter arrives without leaving the stage
Survive for 30 minutes on any official survival map.
As the Spitter, spit on a Survivor who is pinned by a Hunter.
As the Hunter, land a 25 damage pounce.
As the Boomer, vomit on a Survivor without having direct line of sight with them.
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
Rescue three Survivors from a single rescue closet.
As the Spitter, spit on a Survivor who is pinned by a Charger.
Earn a gold medal on every official survival map.
Earn a silver medal on every official survival map.
Earn a bronze medal on every official survival map
Kill a pouncing Hunter with a shotgun.
With a sharp melee weapon, cut a Smoker's tongue before he ensnares you.
Discover the hidden room in the Last Stand campaign
Destroy a Tank's rock in mid-air.
Earn a gold medal on any official survival map.
Earn a silver medal on any official survival map.
Earn a bronze medal on any official Survival map.
Revive an incapacitated teammate while a Tank is nearby.
Survive The Last Stand campaign on any difficulty.
Survive The Last Stand campaign on Expert Realism.
Destroy 20 gascans as the Spitter.
Kill the Witch bride with a single shotgun blast on expert difficulty.
Kill 20 Jockeys with the shovel or pitchfork.
Survive for 10 minutes on any official map in Versus Survival.
Kill 53,599 infected. You made sure the dead won't rise anymore!
Escape Liberty Mall's Atrium before the first Tank appears
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.