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