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