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