Unlockables - Complete each achievement to get the allotted gamerscore.

101 Cremations (20) Set 101 Infected on fire.
Akimbo Assassin (30) Survive an entire campaign using only pistols.
All 4 Dead (30) Kill all four Survivors in one life while playing as a Tank.
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.
Brain Salad (15) Make 100 headshot kills.
Burn the Witch (10) Light a Witch with a Molotov.
Chain Smoker (20) Constrict two Survivors in one life as a Smoker.
Clean Kill (10) Shove a Boomer and then kill him without him splashing on anyone.
Cr0wnd (30) Kill a Witch with a single headshot.
Dead Baron (15) Survive the Dead Air campaign.
Dead Giveaway (10) Heal a fellow Survivor when your own health is below 10.
Dead Stop (10) Punch a Hunter as he is pouncing.
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.
Grim Reaper (15) Survive the Blood Harvest campaign.
Ground Cover (30) Save another Survivor from a Special Infected while on the ground.
Helping Hand (20) Revive 50 incapacitated Survivors.
Hero Closet (10) Rescue a Survivor trapped in a closet.
Hunter Punter (10) Shove a Hunter off of a pinned and helpless Survivor.
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.
Man vs Tank (30) Single-handedly kill a Tank.
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.
No-one Left Behind (20) Beat a campaign with all 4 Survivors.
Nothing Special (30) Survive a campaign with no Survivors taking damage from Special Infected.
Pharm-assist (20) Give pain pills to 10 Survivors.
Pyrotechnician (20) Blow up 20 Infected in a single explosion.
Red Mist (20) Kill 1000 Infected with a mounted machine gun.
Safety First (30) Play an entire campaign with no Survivors taking friendly fire damage.
Spinal Tap (10) Kill an Infected with a single blow from behind.
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.
Toll Collector (15) Survive the Death Toll campaign.
Tongue Twister (20) Free yourself from a Smoker who has grabbed you with his tongue.
Towering Inferno (10) Light a Tank with a Molotov.
Unbreakable (30) Finish a campaign without ever being healed.
Untouchables (30) No Survivors take damage after contacting the rescue vehicle.
What Are You Trying to Prove? (35) Survive all campaigns on Expert.
Witch Hunter (20) Kill a Witch without any Survivor taking damage from her.
Zombicidal Maniac (30) Survive any campaign on Expert.
Zombie Genocidest (20) Kill 53,595 Infected.