- Rudolph, the Bloody Nosed Reindeer
[2010 Xmas] Kill a Christmas Crawler with a Crossbow.
- It's Not Easy Being Greasy
Cause a Specimen to Die by Luring them into Bloat Acid.
- Experimenticenticide
Kill 100 Specimens.
- Trick, not Treat
Kill 5 Halloween Specimens with any gun without reloading
- Fascist Dietitian
Kill 200 Bloats.
- Homer's Heroes
Kill 100 Sirens.
- Keep Those Sneakers Off the Floor!
Kill 20 Stalkers with Explosives.
- Bitter Irony
Kill 2 Scrakes with a Chainsaw in a Single Wave.
- Hot Cross Fun
Kill 25 Burning Specimens with a Crossbow.
- Dignity for the Dead
Kill 10 Specimens Feeding on Dead Teammates Corpses.
- Careful Spender
Kill 4 Specimens with a Single Shot from a Hunting Shotgun.
- Too Close For Comfort
Finish off a Fleshpound using a Melee Attack.
- Master Surgeon
As a Medic, Kill 8 Specimens using a Knife in a Single Wave.
- It's What's Inside That Counts
Turn 500 Specimens into Giblets.
- Quarter Pounder With Ease
Turn 5 Fleshpounds into Giblets.
- Thin-Ice Pirouette
Complete 10 Waves when the Rest of your Team has Died.
- Mr. Perky
Get All of your Perks up to Level 5.
- Experimentilottacide
Kill 10,000 Specimens.
- Hard Boss
Win a Long Game on Offices on Hard Difficulty.
- The Hard War
Complete a Long Game on all 5 Core Maps on Hard Difficulty.
- Suicidal Pub Crawl
Win a Long Game on West London on Suicidal Difficulty.
- Emperor of the Manor
Win a Long Game on Manor on Suicidal Difficulty.
- Alligator Farmer
Win a Long Game on Farm on Suicidal Difficulty.
- The Completely Suicidal War
Complete a Long Game on all 5 Core Maps on Suicidal Difficulty.
- Steel Worker
Win a Long Game on Foundry, on Hard Difficulty.
- Man of Steel
Win a Long Game on Foundry, on Suicidal Difficulty.
- Complete Barking
Win a Long Game on Bedlam, on Suicidal Difficulty.
- Squirrel King of the Dark Forest
Win a Long Game on Wyre, on Normal Difficulty.
- Raccoon King of the Dark Forest
Win a Long Game on Wyre, on Hard Difficulty.
- Bear King of the Dark Forest
Win a Long Game on Wyre, on Suicidal Difficulty.
- Long, Hot Summer
Complete a Long Game on all 3 Summer 2009 maps on Normal Difficulty.
- Summer of 2009
Complete a Long Game on all 3 Summer 2009 maps on Hard Difficulty.
- And Back to School
Complete a Long Game on all 3 Summer 2009 maps on Suicidal Difficulty.
- Explosive Personality
As Demolitions, kill 1000 Specimens with the Pipebomb.
- Flaming Hell, That was Close
As Firebug, kill the Husk with the Flamethrower before he hurts anyone.
- Merry Men
Kill the Patriarch when everyone is ONLY using Crossbows.
- Blooper Reel
Turn 500 Zeds into Giblets using the M79.
- Dot of Doom
Get 25 headshots in a row with the EBR while using the Laser Sight.
- SCAR'd
Kill 1000 Specimens with the SCAR.
- Healing Touch
Heal 200 teammates with the MP7's medication dart.
- Pound This
Kill 100 Fleshpounds with the AA12.
- Killer Junior
Kill 20 crawlers in mid-air with the M79.
- Getting Chunky
Obliterate 10 Zeds at once with the Pipe Bomb.
- Hellish Pub Crawl
Win a Long Game on West London on Hell on Earth Difficulty.
- Demonic King of the Manor
Win a Long Game on Manor on Hell on Earth Difficulty.
- Demon Farmer
Win a Long Game on Farm on Hell on Earth Difficulty.
- Boss from Hell
Win a Long Game on Offices on Hell on Earth Difficulty.
- Scientist from Hell
Win a Long Game on Biotics Lab on Hell on Earth Difficulty.
- Diablo Steel Man
Win a Long Game on Foundry on Hell on Earth Difficulty.
- Commit-ed for life
Win a Long Game on Bedlam on Hell on Earth Difficulty.
- Wolf King of the Dark Forest
Win a Long Game on Wyre on Hell on Earth Difficulty.
- Waste Land
Win a Long Game on Biohazard on Hard Difficulty.
- Waste of Space
Win a Long Game on Biohazard on Suicidal Difficulty.
- Wasted
Win a Long Game on Biohazard on Hell on Earth Difficulty.
- Warehouse Foreman
Win a Long Game on Crash on Suicidal Difficulty.
- Warehouse Manager
Win a Long Game on Crash on Hell on Earth Difficulty.
- Departure Gate
Win a Long Game on Departed on Suicidal Difficulty.
- Dear Departed
Win a Long Game on Departed on Hell on Earth Difficulty.
- Missed Connection
Win a Long Game on Filth's Cross on Hard Difficulty.
- Train Wreck
Win a Long Game on Filth's Cross on Suicidal Difficulty.
- Pile Up
Win a Long Game on Filth's Cross on Hell on Earth Difficulty.
- Gimme a Plaster!
Win a Long Game on Hospital Horrors on Normal Difficulty.
- That Bloody Well Hurts!
Win a Long Game on Hospital Horrors on Hard Difficulty.
- I'm Dying Here!
Win a Long Game on Hospital Horrors on Suicidal Difficulty.
- Not Dead Yet!
Win a Long Game on Hospital Horrors on Hell on Earth Difficulty.
- Crushed Ice
Win a Long Game on Icebreaker on Hard Difficulty.
- Comet
Win a Long Game on Icebreaker on Hell on Earth Difficulty.
- Mountaineer
Win a Long Game on Mountain Pass on Suicidal Difficulty.
- Park Ranger
Win a Long Game on Mountain Pass on Hell on Earth Difficulty.
- Private Security
Win a Long Game on Suburbia on Hard Difficulty.
- Vigilante
Win a Long Game on Suburbia on Suicidal Difficulty.
- SWAT
Win a Long Game on Suburbia on Hell on Earth Difficulty.
- Burst Pipe
Win a Long Game on Waterworks on Hard Difficulty.
- Pressure Failure
Win a Long Game on Waterworks on Suicidal Difficulty.
- Floodgate to Hell
Win a Long Game on Waterworks on Hell on Earth Difficulty.
- Piece of Cake
Complete all new map achievements on Normal Difficulty.
- Pound Cake
Complete all new map achievements on Hard Difficulty.
- Fruit Cake
Complete all new map achievements on Suicidal Difficulty.
- Devil Cake
Complete all new map achievements on Hell On Earth Difficulty.
- Walking in A Winter Horror Land
Win a Long Game on Santa's Evil Lair on Normal Difficulty.
- Silent Night, Evil Night
Win a Long Game on Santa's Evil Lair on Hard Difficulty.
- I'm Dreaming of a Red Christmas
Win a Long Game on Santa's Evil Lair on Suicidal Difficulty.
- Cracked the Nutcracker!
[2010 Xmas] Land the killing blow on a Christmas Fleshpound with a Knife.
- Can't Catch Me!
[2010 Xmas] Kill 2 Christmas Gorefasts with a Melee weapon from behind in one wave.
- That's not Santa!
[2010 Xmas] Kill 3 Christmas Bloats with the Bullpup in one wave.
- Not So Silent Night
[2010 Xmas] Kill a Christmas Siren with an undetonated LAW rocket.
- Tis Better to Give than to Receive
[2010 Xmas] Drop 3 Tier 3 weapons for others (with which they kill at least one Christmas Zed).
- Bad Santa
Unlock 10 of the 13 Christmas Achievements along with any Christmas Map achievement.
- Uber Tuber
Expensive but delicious! Brought to you by Dr. Dougley and Lord Ned.
- Still Alive
Win a Long Game on Aperture on Hard Difficulty.
- This is a Triumph
Win a Long Game on Aperture on Suicidal Difficulty.
- I'm Making a Note Here, Huge Success
Win a Long Game on Aperture on Hell on Earth Difficulty.
- Golden Potato
Get into GLaDOS' core on Aperture.
- Dog and Pony Show
Win a Long Game on Abusement Park on Hard Difficulty.
- 3 Ring Circus
Win a Long Game on Abusement Park on Suicidal Difficulty.
- On Top of the Big Top
Win a Long Game on Abusement Park on Hell on Earth Difficulty.
- Assistant Homicide
Kill 2 Circus Stalkers with a Melee weapon to the back in one wave.
- The Big Hunt
Kill a Circus Scrake with a Crossbow.
- Lifting a Dumbell
Kill a Circus Husk with a LAW.
- Juggling Act
Drop 5 different Tier 2 weapons in one wave.
- Taking Down the Big Top
Kill 4 Circus Zeds in 1 ZED time chain with a Melee weapon.
- Punk'd
Unlock 10 of the 13 Circus Achievements along with any Abusement Park achievement.
- This is No Ordinary Rabbit!
Kill 25 Halloween Scrakes in Bedlam
- Rule The Roost
Get all 6 achievements and unlock Commando Chicken
- Burning Irony
Kill 15 Husks with the Husk Cannon
- Highlander
Kill a Scrake, a Fleshpound, and the Patriarch with the Claymore Sword within one map
- Finish Him
Hit a Scrake with the M203 Rifle grenade to kill him
- I love ze Healing not ze Hurting
Heal others for 3000 points of health with the MP5 SMG
- Italian Meat Pasta
Kill 12 zeds with a full magazine from the Combat Shotgun
- Feeling Lucky?
Kill a specimen with every shot from your Revolver for one magazine
- We Have Ourselves a Cowboy
Hold dual 9mm, dual hand cannons and Dual Revolvers
- On the Rocks
Beat Ice Cave on Suicidal Difficulty
- Anti Freeze
Beat Ice Cave on Hell on Earth Difficulty
- Spec Ops
Kill 12 clots with one magazine without reloading (MK23)
- Fugly
Kill one of each type of zed in one round (HSG Shotgun)
- The Big One
Kill 2 scrakes with one shot (M99)
- Demonic Road
Beat Hellride on Suicidal Difficulty
- Devil's Co-pilot
Beat Hellride on Hell on Earth Difficulty
- Nail'd!
Kill 4 Stalkers in a game with the Vlad9000 Nailgun
- Explosion of Love
Heal yourself plus 5 other players with one grenade
- Trench Warfare
Set a total of 200 Zeds on fire with the Trench Gun in Hillbilly Horror
- Second Cousins
Beat Hillbilly Horror on Hard Difficulty
- First Cousins (Once Removed)
Beat Hillbilly Horror on Suicidal Difficulty
- First Cousins
Beat Hillbilly Horror on Hell on Earth Difficulty
- Grim Reaper
Get the 6 Special Halloween Achievements plus 1 Hillbilly Horror Map Achievement to unlock the Grim Reaper
- Soul Collector
Free the souls of the 25 Gnomes hidden on Hillbilly Horror in 1 game
- Creepy Crawlies
Kill 15 Hillbilly Crawlers in 1 game with the Tommy Gun or MKb42
- Rippin' It Up
Kill a Hillbilly Husk and another Hillbilly Zed in the same shot with the Buzzsaw Bow or M99
- Have my axe
Kill 30 Fleshpounds with the Dwarfs!? axe with back attacks
- One Small Step for Man
Kill 500 Zeds with the Schneidzekk Medic Gun while you are falling
- But It's All Red!
Collect all 16 Z.E.D. Gun pieces
- Game Over, Man!
Have 20 Zeds you slowed with the Z.E.D. gun killed
- Attempting Re-entry
Beat Moonbase on Hard Difficulty
- Amusing Death
Beat Moonbase on Suicidal Difficulty
- One Giant Leap (Back) for Mankind
Beat Moonbase on Hell on Earth Difficulty
- Gimli That Axe!
Get the Not-a-war-hammer Achievement in Dwarfs!?
- Astro Buffer Afficiando
Beat Steamland on Normal Difficulty
- Fractional Neutron Activator
Beat Steamland on Suicidal Difficulty
- Advanced Omega Wave Resonance Explorer
Beat Steamland on Hell on Earth Difficulty
- Simplified Force Adhesion Afficianado
Beat Steamland in Objective Mode on Normal Difficulty
- Oscillating Hydrogen Transition Achiever
Beat Steamland in Objective Mode on Hard Difficulty
- Alpha Wave Osteooxidation Activator
Beat Steamland in Objective Mode on Suicidal Difficulty
- Tachyon Cytoneutralization Explorer
Beat Steamland in Objective Mode on Hell on Earth Difficulty
- Hide and go Puke
[2013 Summer] Destroy all the Pukey the Clown dolls
- Arcade Gamer
[2013 Summer] Complete the Pop the Clot, the Strong Man and the Grenade Toss games
- Full Charge
Have 5 Breaker Boxes 100% repaired at the same time
- Extended Motion Protector
[2013 Summer] Protect the Ringmaster during the escort mission so that he does not get hit more than 15 times
- Guardian Assault Protector
Protect the ringmaster during the defense mission so that he does not get hit more than 15 times
- Golden 3 Crown Note
Get all 3 gold bars without the carriers taking damage while they have them
- Single-shot Equalizer
Kill 4 different types of Zeds with headshots with 4 shots from the Long Musket or the M14 without reloading
- Single-Load Doom Bombardier
Kill a ZED with a direct (unexploded) shot from the Orca Bomb Propeller or the M-79/M32
- Turbo Executioner
Kill 5 zeds in ZED time without reloading with Dr. T's LDS or Bullpup
- Mrs. Punkd
Get 4 of 6 of the 2013 Summer Event in-game level Achievements, one Standard and one Objective Mode map completion Achievement, plus the Punk'd Achievement to unlock Steampunk Mrs. Foster
- Longshoreman
Beat Fright Yard on Normal Difficulty
- Stevedore
Beat Fright Yard on Suicidal Difficulty
- Fork Lift Operator
Beat Fright Yard in Objective Mode on Normal Difficulty
- Truck Driver
Beat Fright Yard in Objective Mode on Hard Difficulty
- Crane Operator
Beat Fright Yard in Objective Mode on Suicidal Difficulty
- Shipping Magnate
Beat Fright Yard in Objective Mode on Hell on Earth Difficulty
- Claw Machine Master
Attach the crane hook within 125 seconds
- Ex-scientist
Collect all the bile without a contamination
- 777
Win Fuel on the first try
- Blinding Big Brother
Destroy all 30 Cameras
- Fire and Forget
Kill a Halloween Fleshpound and Scrake in the same explosion with the Seal Squeal Harpoon Bomber or the LAW
- Under The Weather
Use Bile or the Flamethrower to kill one of each Halloween Zed
- Most Bang for the Buck
Kill 10 Halloween zeds in explosions using the Seeker 6 or the M32 within 5 seconds
- Death
Beat Hell on Normal Difficulty
- King Minos
Beat Hell on Hard Difficulty
- Cerberus
Beat Hell on Suicidal Difficulty
- Lucifer
Beat Hell on Hell on Earth Difficulty
- Agnosia
Beat Forgotten on Hard Difficulty
- Amnesia
Beat Forgotten on Suicidal Difficulty
- Dementia
Beat Forgotten on Hell on Earth Difficulty
- No Time for Love, Dr. Jones
Win a short round on KF-Hell playing as or with Harchier Spebbington
- Home Brewer
Beat Siren's Belch on Normal Difficulty
- Micro Brewer
Beat Siren's Belch on Hard Difficulty
- Master Brewer
Beat Siren's Belch on Suicidal Difficulty
- Trappist Monk
Beat Siren's Belch on Hell on Earth Difficulty
- Oktoberfest Master
Collect all the Beer Steins
- Squire
Beat Stronghold on Hard Difficulty
- Prince
Beat Stronghold on Suicidal Difficulty
- King
Beat Stronghold on Hell on Earth Difficulty
- Rich Evil Uncle
Collect all the Treasure Bags
- Cattle Class
Beat Transit on Normal Difficulty
- Business Class
Beat Transit on Suicidal Difficulty
- First Class
Beat Transit on Hell on Earth Difficulty
- Day-trip
Beat Transit in Objective Mode on Normal Difficulty
- Long weekend
Beat Transit in Objective Mode on Hard Difficulty
- Serious vacation
Beat Transit in Objective Mode on Suicidal Difficulty
- Moved to Paris!
Beat Transit in Objective Mode on Hell on Earth Difficulty
- Nitro Boost!
Transit - Get the Nitro to the Objective in 135 seconds or less
- Totally Metal
Transit - Kill 250 Zeds before completing the welding objective
- Multi-pass
Transit - Pick up the door key
- Science Hater
Transit - Destroy all the DNA vials
- Doctor WHO??
Transit - Get all Objective achievements AND beat KFO Transit on Hard or above to unlock Dr Rachel Clamely.
- Gone clubbing
Beat Clandestine on Normal Difficulty
- Rack 'em up
Beat Clandestine on Hard Difficulty
- Burned out
Beat Clandestine on Suicidal Difficulty
- Hangover from Hell
Beat Clandestine on Hell Difficulty
- Skull Cracker
Clandestine - Destroy 30 skulls
- Cave of Wonder
Beat ThrillsChills on Normal Difficulty
- Grotto of Terror
Beat ThrillsChills on Suicidal Difficulty
- Hollow of Horror
Beat ThrillsChills on Hell Difficulty