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