Full list of all 65 Left 4 Dead achievements worth 1,500 gamerscore. It takes around 40-50 hours to unlock all of the achievements in the base game on Xbox 360.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 3 DLC packs containing 15 achievements worth 500 Gamerscore.
Survive all campaigns on Expert.
Kill 53,595 Infected.
Survive a campaign with no Survivors taking damage from Special Infected.
All Survivors complete a campaign without being vomited on.
No Survivors take damage after contacting the rescue vehicle.
Survive any campaign on Expert.
Play an entire campaign with no Survivors taking friendly fire damage.
Dole out 5000 total Survivor damage as a Special Infected.
Kill all four Survivors in one life while playing as a Tank.
Kill 1000 Infected with a mounted machine gun.
Single-handedly kill a Tank.
Revive 50 incapacitated Survivors.
Drag a Survivor 100 feet with your tongue.
Cover four Survivors with Boomer bile at once.
As an Infected, incap a Survivor who has entered and left a safe room.
Shove a Boomer and then kill him without him splashing on anyone.
Survive the Blood Harvest campaign.
Survive a campaign without being incapacitated.
Constrict two Survivors in one life as a Smoker.
Save another Survivor from a Special Infected while on the ground.
Pounce two different Survivors in one life as a Hunter.
Light a Tank with a Molotov.
Survive the Dead Air campaign.
Finish a campaign without ever being healed.
Beat a campaign with all 4 Survivors.
Give pain pills to 10 Survivors.
Kill an Infected with a single blow from behind.
Kill a Witch without any Survivor taking damage from her.
Kill a Witch with a single headshot.
Set 101 Infected on fire.
You or another Survivor take no damage after being vomited on by a Boomer.
Kill 10 Smokers as they are pulling helpless Survivors.
Rescue a Survivor trapped in a closet.
Heal a fellow Survivor when your own health is below 10.
Headshot a Hunter while he's leaping.
Blow up 20 Infected in a single explosion.
Survive the Death Toll campaign.
Survive an entire campaign using only pistols.
Heal 25 Survivors with a first aid kit.
Punch a Hunter as he is pouncing.
Shove a Hunter off of a pinned and helpless Survivor.
Light a Witch with a Molotov.
Leave a safe room to save an incapped teammate and bring them back safely.
Free yourself from a Smoker who has grabbed you with his tongue.
Protect any Survivor from an attacking Infected 50 times.
Rescue a Survivor from a Smoker's tongue before he takes damage.
Sneak past all Witches in a campaign without disturbing one.
Survive the No Mercy campaign.
Make 100 headshot kills.
Kill a Tank without it dealing any damage to a Survivor.
Smoker pull a bile-covered Survivor until you hold him during Crash Course.
Your team wipes all Survivors after the escape vehicle has opened in Crash Course.
Kill 5,359 Infected in the Crash Course campaign.
Win a Versus campaign of Crash Course.
Your team incapacitates three Survivors within five seconds in the Crash Course campaign.
Pounce a Survivor for 25 points of damage in the Crash Course campaign.
Restart the generator within 30 seconds of it shutting off in the Crash Course campaign.
Survive the Crash Course Campaign.
Stun a Tank with an explosion in the Crash Course campaign.
As a Tank hit 20 Survivors with a car in the Crash Course campaign.
As a Special Infected, incap someone who is trying to sacrifice themselves.
Have all 3 generators running at once in "The Sacrifice" finale.
Kill a Special Infected with an exploding barrel.
Have Bill sacrifice himself for the team.
Complete "The Sacrifice".