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.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
Revive 10 dead Survivors with the defibrillator.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Collect 100 gas cans in Scavenge.
Cause 25 gas can drops as a Special Infected.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Survive all campaigns on Expert.
Cross the bridge finale in less than three minutes.
Survive the Parish campaign.
Survive the Hard Rain campaign.
Navigate the sugar mill and reach the safe room without killing any Witches.
Stop the enemy team from collecting any gas cans during a Scavenge round.
Win a game of Scavenge.
Make a Survivor drop a gas can during overtime.
Collect 15 gas cans in a single Scavenge round.
Rescue Gnome Chompski from the Carnival.
Survive a campaign on Expert skill with Realism mode enabled.
Survive the Swamp Fever campaign.
Defend yourself at the crashed airliner without taking damage.
Kill 10 swampy Mudmen while they are in the water.
In a Survival round, get a medal only using melee weapons.
Plays games with free weekend players and helps them survive a campaign.
Decapitate 200 Infected with a melee weapon.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
Survive the Dark Carnival campaign.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Prove you are faster than Moustachio.
Prove you are stronger than Moustachio.
Honk the noses of 10 Clowns.
Kill one of each Uncommon Infected.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Kill a Charger with a melee weapon while they are charging.
Use every melee weapon to kill Common Infected.
As the Charger, grab a Survivor and carry them over 80 feet.
Use a bile bomb on a Tank.
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.
As the Spitter, spit on a Survivor being choked by a Smoker.
Finish a campaign using only melee weapons.
Kill a Tank with melee weapons.
Spread cheer by helping a free holiday player survive a campaign.
Kill 15 Infected with a single grenade launcher blast.
Kill 100 Common Infected with the chainsaw.
Deploy an ammo upgrade and have your team use it.
Ignite 50 Common Infected with incendiary ammo.
Survive the Dead Center campaign.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
As the Charger, bowl through the entire enemy team in a single charge.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
As the Jockey, ride a Survivor for more than 12 seconds.
Kill a Spitter before she is able to spit.
As the Spitter, hit every Survivor with a single acid patch.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Play 5 full games of Scavenge on The Port.
Collect 10 items dropped by a Fallen Survivor.
Open 5 foot lockers.
Using the M60, kill 25 infected without letting go of the trigger.
Play the new Midnight Riders song on a jukebox.
Kill a Tank only with damage from the original Survivors.
Survive The Passing Campaign.
Knock off the heads of 18 infected with the golf club.
Play 6 Mutations.
As a Special Infected, incap someone who is trying to sacrifice themselves.
Complete "The Sacrifice".
Have Bill sacrifice himself for the team.
Have all 3 generators running at once in "The Sacrifice" finale.
Kill a Special Infected with an exploding barrel.
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!
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
Survive for 10 minutes on any official map in Versus Survival.
Survive for 30 minutes on any official survival map.
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Escape Liberty Mall's Atrium before the first Tank appears
On the concert finale, survive until the helicopter arrives without leaving the stage
Destroy 20 gascans as the Spitter.
Kill 20 Jockeys with the shovel or pitchfork.
Earn a gold medal on any official survival map.
Instantly kill a Survivor as the Charger.
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
Kill a pouncing Hunter with a shotgun.
Survive The Last Stand campaign on any difficulty.
Survive The Last Stand campaign on Expert Realism.
Destroy a Tank's rock in mid-air.
Discover the hidden room in the Last Stand campaign
Kill the Witch bride with a single shotgun blast on expert difficulty.
Rescue three Survivors from a single rescue closet.
As the Spitter, spit on a Survivor who is pinned by a Hunter.
With a sharp melee weapon, cut a Smoker's tongue before he ensnares you.
As the Spitter, spit on a Survivor who is pinned by a Charger.
Revive an incapacitated teammate while a Tank is nearby.
Earn a silver medal on any official survival map.
Earn a bronze medal on any official Survival map.
As the Hunter, land a 25 damage pounce.
As the Boomer, vomit on a Survivor without having direct line of sight with them.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.