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