Here are ALL 50 of the achievements and and what needs to be done to get them. They are worth a total of 1,000 points.

Burn the Witch (10)
Light a Witch with a Molotov.

Clean Kill (10)
Shove a Boomer and then kill him without him splashing on anyone.

Dead Giveaway (10)
Heal a fellow Survivor when your own health is below 10.

Dead Stop (10)
Punch a Hunter as he is pouncing.

Hero Closet (10)
Rescue a Survivor trapped in a closet.

Hunter Punter (10)
Shove a Hunter off of a pinned and helpless Survivor.

Spinal Tap (10)
Kill an Infected with a single blow from behind.

Towering Inferno (10)
Light a Tank with a Molotov.

Brain Salad (15)
Make 100 headshot kills.

Dead Baron (15)
Survive the ‘Dead Air’ campaign.

Grim Reaper (15)
Survive the ‘Blood Harvest’ campaign.

Mercy Killer (15)
Survive the ‘No Mercy’ campaign.

My Bodyguard (15)
Protect any Survivor from an attacking Infected 50 times.

No Smoking Section (15)
Kill 10 Smokers as they are pulling helpless Survivors.

Toll Collector (15)
Survive the ‘Death Toll’ campaign.

101 Cremations (20)
Set 101 Infected on fire.

Back 2 Help (20)
Leave a safe room to save an incapped teammate and bring them back safely.

Barf Bagged (20)
Cover four Survivors with Boomer bile at once.

Big Drag (20)
Drag a Survivor 100 feet with your tongue.

Blind Luck (20)
You or another Survivor take no damage after being vomited on by a Boomer.

Chain Smoker (20)
Constrict two Survivors in one life as a Smoker.

Dead Wreckening (20)
Dole out 5000 total Survivor damage as a Special Infected.

Do Not Disturb (20)
Sneak past ALL Witches in a campaign without disturbing one.

Double Jump (20)
Pounce two different Survivors in one life as a Hunter.

Drag and Drop (20)
Rescue a Survivor from a Smoker’s tongue before he takes damage.

Field Medic (20)
Heal 25 Survivors with a first aid kit.

Helping Hand (20)
Revive 50 incapacitated Survivors.

Jump Shot (20)
Headshot a Hunter while he’s leaping.

Lamb 2 Slaughter (20)
As an Infected, incap a Survivor who has entered and left a safe room.

No-one Left Behind (20)
Beat a campaign with ALL 4 Survivors.

Pharm-assist (20)
Give pain pills to 10 Survivors.

Pyrotechnician (20)
Blow up 20 Infected in a single explosion.

Red Mist (20)
Kill 1,000 Infected with a mounted machine gun.

Stand Tall (20)
Survive a campaign without being incapacitated.

Stomach Upset (20)
ALL Survivors complete a campaign without being vomited on.

Tankbusters (20)
Kill a Tank without it dealing any damage to a Survivor.

Tongue Twister (20)
Free yourself from a Smoker who has grabbed you with his tongue.

Witch Hunter (20)
Kill a Witch without any Survivor taking damage from her.

Zombie Genocidest (20)
Kill 53,595 Infected.

Akimbo Assassin (30)
Survive an entire campaign using only pistols.

All 4 Dead (30)
Kill ALL 4 Survivors in one life while playing as a Tank.

Crownd (30)
Kill a Witch with a single headshot.

Ground Cover (30)
Save another Survivor from a Special Infected while on the ground.

Man Vs Tank (30)
Single-handedly kill a Tank.

Nothing Special (30)
Survive a campaign with no Survivors taking damage from Special Infected.

Safety First (30)
Play an entire campaign with no Survivors taking friendly fire damage.

Unbreakable (30)
Finish a campaign without ever being healed.

Untouchables (30)
No Survivors take damage after contacting the rescue vehicle.

Zombicidal Maniac (30)
Survive any campaign on Expert difficulty setting.

What Are You Trying To Prove? (35)
Survive ALL campaigns on Expert difficulty setting.