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.
Survive a campaign on Expert skill with Realism mode enabled.
Navigate the sugar mill and reach the safe room without killing any Witches.
Finish a campaign using only melee weapons.
Plays games with free weekend players and helps them survive a campaign.
Kill 15 Infected with a single grenade launcher blast.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Cross the bridge finale in less than three minutes.
Survive all campaigns on Expert.
Collect 15 gas cans in a single Scavenge round.
Win a game of Scavenge.
Defend yourself at the crashed airliner without taking damage.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Revive 10 dead Survivors with the defibrillator.
Kill a Tank with melee weapons.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
Prove you are stronger than Moustachio.
As the Jockey, ride a Survivor for more than 12 seconds.
Survive the Hard Rain campaign.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
Prove you are faster than Moustachio.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Kill 10 swampy Mudmen while they are in the water.
Kill 100 Common Infected with the chainsaw.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
Rescue Gnome Chompski from the Carnival.
As the Spitter, hit every Survivor with a single acid patch.
Decapitate 200 Infected with a melee weapon.
Use every melee weapon to kill Common Infected.
Survive the Dark Carnival campaign.
Spread cheer by helping a free holiday player survive a campaign.
Ignite 50 Common Infected with incendiary ammo.
Honk the noses of 10 Clowns.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Use a bile bomb on a Tank.
Survive the Parish campaign.
Kill a Spitter before she is able to spit.
Kill one of each Uncommon Infected.
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 Jockey, ride the Survivors twice in a single life.
Survive the Swamp Fever campaign.
Survive the Dead Center campaign.
Deploy an ammo upgrade and have your team use it.
Kill a Charger with a melee weapon while they are charging.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
As the Spitter, spit on a Survivor being choked by a Smoker.
In a Survival round, get a medal only using melee weapons.
Collect 100 gas cans in Scavenge.
Stop the enemy team from collecting any gas cans during a Scavenge round.
Make a Survivor drop a gas can during overtime.
Cause 25 gas can drops as a Special Infected.
Using the M60, kill 25 infected without letting go of the trigger.
Play the new Midnight Riders song on a jukebox.
Play 6 Mutations.
Collect 10 items dropped by a Fallen Survivor.
Open 5 foot lockers.
Survive The Passing Campaign.
Kill a Tank only with damage from the original Survivors.
Knock off the heads of 18 infected with the golf club.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Play 5 full games of Scavenge on The Port.
Kill a Special Infected with an exploding barrel.
Complete "The Sacrifice".
Have Bill sacrifice himself for the team.
Have all 3 generators running at once in "The Sacrifice" finale.
As a Special Infected, incap someone who is trying to sacrifice themselves.
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.
Instantly kill a Survivor as the Charger.
Kill 53,599 infected. You made sure the dead won't rise anymore!
Rescue three Survivors from a single rescue closet.
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.
Discover the hidden room in the Last Stand campaign
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
On the concert finale, survive until the helicopter arrives without leaving the stage
As the Boomer, vomit on a Survivor without having direct line of sight with them.
As the Spitter, spit on a Survivor who is pinned by a Hunter.
Escape Liberty Mall's Atrium before the first Tank appears
Kill a pouncing Hunter with a shotgun.
Earn a gold medal on any official survival map.
Earn a silver medal on any official survival map.
Destroy a Tank's rock in mid-air.
Revive an incapacitated teammate while a Tank is nearby.
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.
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
Destroy 20 gascans as the Spitter.
Kill the Witch bride with a single shotgun blast on expert difficulty.
As the Hunter, land a 25 damage pounce.
Kill 20 Jockeys with the shovel or pitchfork.
Survive for 10 minutes on any official map in Versus Survival.
Earn a bronze medal on every official survival map
Earn a silver medal on every official survival map.
Earn a gold medal on every official survival map.
Survive for 30 minutes on any official survival map.
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.