Win a Long Game on West London on Normal Difficulty.

Win a Long Game on Manor on Normal Difficulty.

Win a Long Game on Biotics Lab on Normal Difficulty.

Win a Long Game on Farm on Normal Difficulty.

Win a Long Game on Offices on Normal Difficulty.

Complete a Long Game on all 5 Core Maps on Normal Difficulty.

Kill 100 Specimens.

Kill 200 Bloats.

Kill 100 Sirens.

Kill 20 Stalkers with Explosives.

Kill 15 Specimens with a Fire Axe in a Single Wave.

Kill 2 Scrakes with a Chainsaw in a Single Wave.

Kill 25 Burning Specimens with a Crossbow.

Kill 10 Specimens Feeding on Dead Teammates Corpses.

Kill 8 Specimens with One Grenade.

Kill 4 Specimens with a Single Shot from a Hunting Shotgun.

Cause a Specimen to Die by Luring them into Bloat Acid.

Finish off a Fleshpound using a Melee Attack.

As a Medic, Kill 8 Specimens using a Knife in a Single Wave.

Turn 500 Specimens into Giblets.

Turn 5 Fleshpounds into Giblets.

In Co-op Mode, Use Syringe on Yourself 100 Times.

Complete 10 Waves when the Rest of your Team has Died.

Give 1,000 Pounds to Teammates who have 50% of Your Cash or Less.

Aquire 5 Minutes of "Zed-Time".

Get All of your Perks up to Level 5.

Kill the Patriarch Before he has a Chance to Heal.

Deliver the Killing Blow to the Patriarch with a L.A.W. Rocket.

Defeat the Patriarch on Suicidal.

Kill 1,000 Specimens.

Kill 10,000 Specimens.

Win a Long Game on West London on Hard Difficulty.

Win a Long Game on Manor on Hard Difficulty.

Win a Long Game on Farm on Hard Difficulty.

Win a Long Game on Offices on Hard Difficulty.

Win a Long Game on Biotics Lab on Hard Difficulty.

Complete a Long Game on all 5 Core Maps on Hard Difficulty.

Win a Long Game on West London on Suicidal Difficulty.

Win a Long Game on Manor on Suicidal Difficulty.

Win a Long Game on Farm on Suicidal Difficulty.

Win a Long Game on Offices on Suicidal Difficulty.

Win a Long Game on Biotics Lab on Suicidal Difficulty.

Complete a Long Game on all 5 Core Maps on Suicidal Difficulty.

Win a Long Game on Foundry, on Normal Difficulty.

Win a Long Game on Foundry, on Hard Difficulty.

Win a Long Game on Foundry, on Suicidal Difficulty.

Win a Long Game on Bedlam, on Normal Difficulty.

Win a Long Game on Bedlam, on Hard Difficulty.

Win a Long Game on Bedlam, on Suicidal Difficulty.

Win a Long Game on Wyre, on Normal Difficulty.

Win a Long Game on Wyre, on Hard Difficulty.

Win a Long Game on Wyre, on Suicidal Difficulty.

Complete a Long Game on all 3 Summer 2009 maps on Normal Difficulty.

Complete a Long Game on all 3 Summer 2009 maps on Hard Difficulty.

Complete a Long Game on all 3 Summer 2009 maps on Suicidal Difficulty.

As Demolitions, kill 1000 Specimens with the Pipebomb.

As Firebug, kill the Husk with the Flamethrower before he hurts anyone.

Kill the Patriarch when everyone is ONLY using Crossbows.

Turn 500 Zeds into Giblets using the M79.

Get 25 headshots in a row with the EBR while using the Laser Sight.

Kill 1000 Specimens with the SCAR.

Heal 200 teammates with the MP7's medication dart.

Kill 100 Fleshpounds with the AA12.

Kill 20 crawlers in mid-air with the M79.

Obliterate 10 Zeds at once with the Pipe Bomb.

Win a Long Game on West London on Hell on Earth Difficulty.

Win a Long Game on Manor on Hell on Earth Difficulty.

Win a Long Game on Farm on Hell on Earth Difficulty.

Win a Long Game on Offices on Hell on Earth Difficulty.

Win a Long Game on Biotics Lab on Hell on Earth Difficulty.

Win a Long Game on Foundry on Hell on Earth Difficulty.

Win a Long Game on Bedlam on Hell on Earth Difficulty.

Win a Long Game on Wyre on Hell on Earth Difficulty.

Win a Long Game on Biohazard on Normal Difficulty.

Win a Long Game on Biohazard on Hard Difficulty.

Win a Long Game on Biohazard on Suicidal Difficulty.

Win a Long Game on Biohazard on Hell on Earth Difficulty.

Win a Long Game on Crash on Normal Difficulty.

Win a Long Game on Crash on Hard Difficulty.

Win a Long Game on Crash on Suicidal Difficulty.

Win a Long Game on Crash on Hell on Earth Difficulty.

Win a Long Game on Departed on Normal Difficulty.

Win a Long Game on Departed on Hard Difficulty.

Win a Long Game on Departed on Suicidal Difficulty.

Win a Long Game on Departed on Hell on Earth Difficulty.

Win a Long Game on Filth's Cross on Normal Difficulty.

Win a Long Game on Filth's Cross on Hard Difficulty.

Win a Long Game on Filth's Cross on Suicidal Difficulty.

Win a Long Game on Filth's Cross on Hell on Earth Difficulty.

Win a Long Game on Hospital Horrors on Normal Difficulty.

Win a Long Game on Hospital Horrors on Hard Difficulty.

Win a Long Game on Hospital Horrors on Suicidal Difficulty.

Win a Long Game on Hospital Horrors on Hell on Earth Difficulty.

Win a Long Game on Icebreaker on Normal Difficulty.

Win a Long Game on Icebreaker on Hard Difficulty.

Win a Long Game on Icebreaker on Suicidal Difficulty.

Win a Long Game on Icebreaker on Hell on Earth Difficulty.

Win a Long Game on Mountain Pass on Normal Difficulty.

Win a Long Game on Mountain Pass on Hard Difficulty.

Win a Long Game on Mountain Pass on Suicidal Difficulty.

Win a Long Game on Mountain Pass on Hell on Earth Difficulty.

Win a Long Game on Suburbia on Normal Difficulty.

Win a Long Game on Suburbia on Hard Difficulty.

Win a Long Game on Suburbia on Suicidal Difficulty.

Win a Long Game on Suburbia on Hell on Earth Difficulty.

Win a Long Game on Waterworks on Normal Difficulty.

Win a Long Game on Waterworks on Hard Difficulty.

Win a Long Game on Waterworks on Suicidal Difficulty.

Win a Long Game on Waterworks on Hell on Earth Difficulty.

Complete all new map achievements on Normal Difficulty.

Complete all new map achievements on Hard Difficulty.

Complete all new map achievements on Suicidal Difficulty.

Complete all new map achievements on Hell On Earth Difficulty.

Get 1000 points of burn damage with the MAC-10.

Win a Long Game on Santa's Evil Lair on Normal Difficulty.

Win a Long Game on Santa's Evil Lair on Hard Difficulty.

Win a Long Game on Santa's Evil Lair on Suicidal Difficulty.

Win a Long Game on Santa's Evil Lair on Hell on Earth Difficulty.

[2010 Xmas] Kill the Christmas Patriarch.

[2010 Xmas] Land the killing blow on a Christmas Fleshpound with a Knife.

[2010 Xmas] Kill 2 Christmas Gorefasts with a Melee weapon from behind in one wave.

[2010 Xmas] Kill the Christmas Scrake with a Fire-based weapon.

[2010 Xmas] Kill 3 Christmas Bloats with the Bullpup in one wave.

[2010 Xmas] Kill a Christmas Crawler with a Crossbow.

[2010 Xmas] Kill a Christmas Siren with an undetonated LAW rocket.

[2010 Xmas] Kill 3 Christmas Stalkers with a Lever Action Rifle without reloading.

[2010 Xmas] Kill a Christmas Husk with any Pistol.

[2010 Xmas] Kill 3 Christmas Zeds in 1 ZED time chain with a Melee weapon.

[2010 Xmas] Drop 3 Tier 3 weapons for others (with which they kill at least one Christmas Zed).

[2010 Xmas] Get covered in Christmas Bloat Bile and live for 10 seconds on Hard, Suicidal, or Hell on Earth.

Unlock 10 of the 13 Christmas Achievements along with any Christmas Map achievement.

[2010 Xmas] Kill 20 Christmas Clots in one wave.

Expensive but delicious! Brought to you by Dr. Dougley and Lord Ned.

Win a Long Game on Aperture on Normal Difficulty.

Win a Long Game on Aperture on Hard Difficulty.

Win a Long Game on Aperture on Suicidal Difficulty.

Win a Long Game on Aperture on Hell on Earth Difficulty.

Get into GLaDOS' core on Aperture.

Win a Long Game on Abusement Park on Normal Difficulty.

Win a Long Game on Abusement Park on Hard Difficulty.

Win a Long Game on Abusement Park on Suicidal Difficulty.

Win a Long Game on Abusement Park on Hell on Earth Difficulty.

Kill the "Ring Leader" (Circus Patriarch)

Kill a Circus Gorefast with a Melee weapon.

Kill 2 Circus Stalkers with a Melee weapon to the back in one wave.

Kill 5 Circus Crawlers with a Bullpup in one wave.

Kill 5 Circus Bloats in one game.

Kill a Circus Scrake with a Crossbow.

Kill a Circus Husk with a LAW.

Kill 3 Circus Clots in a wave with the Lever Action Rifle.

Land the killing blow on a Circus Fleshpound with a Pistol.

Drop 5 different Tier 2 weapons in one wave.

Survive 10 seconds after being screamed at by a Circus Siren on Hard or above.

Kill 4 Circus Zeds in 1 ZED time chain with a Melee weapon.

Kill 10 Circus Clots with a Fire-based weapon.

Unlock 10 of the 13 Circus Achievements along with any Abusement Park achievement.

Kill The Vampire Patriarch Ringmaster in Bedlam

Decapitate a burning Halloween specimen in Bedlam

Kill 250 Halloween Specimens in Bedlam

Win a Long Bedlam Match During the Halloween Event on Hard

Kill 25 Halloween Scrakes in Bedlam

Kill 5 Halloween Specimens with any gun without reloading

Get all 6 achievements and unlock Commando Chicken

Kill 15 Husks with the Husk Cannon

Kill a Scrake, a Fleshpound, and the Patriarch with the Claymore Sword within one map

Kill 1 specimen ONLY while expending a full M4 Assault Rifle magazine

Hit a Scrake with the M203 Rifle grenade to kill him

Heal others for 3000 points of health with the MP5 SMG

Kill 12 zeds with a full magazine from the Combat Shotgun

Kill a specimen with every shot from your Revolver for one magazine

Hold dual 9mm, dual hand cannons and Dual Revolvers

Beat Ice Cave on Normal Difficulty

Beat Ice Cave on Hard Difficulty

Beat Ice Cave on Suicidal Difficulty

Beat Ice Cave on Hell on Earth Difficulty

Kill 15 XMas Clots, 5 xmas Stalkers, 5 XMas Crawlers, 1 XMas Siren and 1 XMas Bloat.

Kill 12 clots with one magazine without reloading (MK23)

Kill a zed that has injured a player (M7A3 rifle)

Kill one of each type of zed in one round (HSG Shotgun)

Kill a zed each with both the Bullpup and FN-Fal

Kill 2 scrakes with one shot (M99)

Beat Hellride on Normal Difficulty

Beat Hellride on Hard Difficulty

Beat Hellride on Suicidal Difficulty

Beat Hellride on Hell on Earth Difficulty

Kill 6 Zeds with one magazine on an MKb42, without reloading

Kill 4 Stalkers in a game with the Vlad9000 Nailgun

Heal yourself plus 5 other players with one grenade

Set a total of 200 Zeds on fire with the Trench Gun in Hillbilly Horror

Beat Hillbilly Horror on Normal Difficulty

Beat Hillbilly Horror on Hard Difficulty

Beat Hillbilly Horror on Suicidal Difficulty

Beat Hillbilly Horror on Hell on Earth Difficulty

Get the 6 Special Halloween Achievements plus 1 Hillbilly Horror Map Achievement to unlock the Grim Reaper

Free the souls of the 25 Gnomes hidden on Hillbilly Horror in 1 game

Kill 1000 Hillbilly Zeds

Kill 15 Hillbilly Crawlers in 1 game with the Tommy Gun or MKb42

Kill a Hillbilly Husk and another Hillbilly Zed in the same shot with the Buzzsaw Bow or M99

Kill 5 Hillbilly Zeds in 10 seconds with the Scythe or Axe

Set 3 Hillbilly Gorefasts on fire with the Flare Pistol or Trench Gun

Kill 30 Fleshpounds with the Dwarfs!? axe with back attacks

Kill 500 Zeds with the Schneidzekk Medic Gun while you are falling

Collect all 16 Z.E.D. Gun pieces

Have 20 Zeds you slowed with the Z.E.D. gun killed

Beat Moonbase on Normal Difficulty

Beat Moonbase on Hard Difficulty

Beat Moonbase on Suicidal Difficulty

Beat Moonbase on Hell on Earth Difficulty

Get the Not-a-war-hammer Achievement in Dwarfs!?

Beat Steamland on Normal Difficulty

Beat Steamland on Hard Difficulty

Beat Steamland on Suicidal Difficulty

Beat Steamland on Hell on Earth Difficulty

Beat Steamland in Objective Mode on Normal Difficulty

Beat Steamland in Objective Mode on Hard Difficulty

Beat Steamland in Objective Mode on Suicidal Difficulty

Beat Steamland in Objective Mode on Hell on Earth Difficulty

[2013 Summer] Destroy all the Pukey the Clown dolls

[2013 Summer] Complete the Pop the Clot, the Strong Man and the Grenade Toss games

Have 5 Breaker Boxes 100% repaired at the same time

[2013 Summer] Protect the Ringmaster during the escort mission so that he does not get hit more than 15 times

Protect the ringmaster during the defense mission so that he does not get hit more than 15 times

Get all 3 gold bars without the carriers taking damage while they have them

Kill 4 different types of Zeds with headshots with 4 shots from the Long Musket or the M14 without reloading

Push a scrake back with the direct fire from a Hunting Shotgun or alt fire from the Multi-Chamber ZED Thrower

Kill a ZED with a direct (unexploded) shot from the Orca Bomb Propeller or the M-79/M32

Kill 5 zeds in ZED time without reloading with Dr. T's LDS or Bullpup

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

Beat Fright Yard on Normal Difficulty

Beat Fright Yard on Hard Difficulty

Beat Fright Yard on Suicidal Difficulty

Beat Fright Yard on Hell on Earth Difficulty

Beat Fright Yard in Objective Mode on Normal Difficulty

Beat Fright Yard in Objective Mode on Hard Difficulty

Beat Fright Yard in Objective Mode on Suicidal Difficulty

Beat Fright Yard in Objective Mode on Hell on Earth Difficulty

Attach the crane hook within 125 seconds

Collect all the bile without a contamination

Win Fuel on the first try

Destroy all 30 Cameras

Kill a Halloween Fleshpound and Scrake in the same explosion with the Seal Squeal Harpoon Bomber or the LAW

Use Bile or the Flamethrower to kill one of each Halloween Zed

Kill 10 Halloween zeds in explosions using the Seeker 6 or the M32 within 5 seconds

Beat Hell on Normal Difficulty

Beat Hell on Hard Difficulty

Beat Hell on Suicidal Difficulty

Beat Hell on Hell on Earth Difficulty

Beat Forgotten on Normal Difficulty

Beat Forgotten on Hard Difficulty

Beat Forgotten on Suicidal Difficulty

Beat Forgotten on Hell on Earth Difficulty

Win a short round on KF-Hell playing as or with Harchier Spebbington

Beat Siren's Belch on Normal Difficulty

Beat Siren's Belch on Hard Difficulty

Beat Siren's Belch on Suicidal Difficulty

Beat Siren's Belch on Hell on Earth Difficulty

Collect all the Beer Steins

Beat Stronghold on Normal Difficulty

Beat Stronghold on Hard Difficulty

Beat Stronghold on Suicidal Difficulty

Beat Stronghold on Hell on Earth Difficulty

Collect all the Treasure Bags

Beat Transit on Normal Difficulty

Beat Transit on Hard Difficulty

Beat Transit on Suicidal Difficulty

Beat Transit on Hell on Earth Difficulty

Beat Transit in Objective Mode on Normal Difficulty

Beat Transit in Objective Mode on Hard Difficulty

Beat Transit in Objective Mode on Suicidal Difficulty

Beat Transit in Objective Mode on Hell on Earth Difficulty

Transit - Get the Nitro to the Objective in 135 seconds or less

Transit - Kill 250 Zeds before completing the welding objective

Transit - Pick up the door key

Transit - Destroy all the DNA vials

Transit - Get all Objective achievements AND beat KFO Transit on Hard or above to unlock Dr Rachel Clamely.

Beat Clandestine on Normal Difficulty

Beat Clandestine on Hard Difficulty

Beat Clandestine on Suicidal Difficulty

Beat Clandestine on Hell Difficulty

Clandestine - Destroy 30 skulls

Beat ThrillsChills on Normal Difficulty

Beat ThrillsChills on Hard Difficulty

Beat ThrillsChills on Suicidal Difficulty

Beat ThrillsChills on Hell Difficulty

Destroy all (15) Snow Globes