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