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