Full list of all 93 Back 4 Blood achievements. It takes around 120-150 hours to unlock all of the achievements in the base game on Windows.
The base game contains 55 achievements, and there are 3 DLC packs containing 38 achievements.
Find the secret in Blue Dog Hollow.
Complete a mission with each of the original Cleaners.
Kill a Monstrous Breaker after removing all of its armor.
Complete Act 4 on Veteran difficulty or higher.
Complete all Act 3 maps on Veteran difficulty or higher.
Kill 15 enemies while downed.
Complete all Act 2 maps on Veteran difficulty or higher.
Find the secret in Plan B.
Complete all Act 1 maps on Veteran difficulty or higher.
Kill an Ogre with the Howitzer.
Safely descend the ladder in the construction zone in Resurgence.
Complete Act 4 on Recruit difficulty or higher.
Complete Remnants.
Complete all Act 3 maps on Recruit difficulty or higher.
Complete Dr. Rogers' Neighborhood.
Find the secret in Dr. Rogers' Neighborhood.
Revive a fallen teammate.
Complete a level while getting at least 50 kills with melee weapons.
Complete Job 10:22.
Complete all Act 2 maps on Recruit difficulty or higher.
Complete Plan B.
Form a party in Fort Hope.
Complete The Armory.
Kill 10 Ridden with Bob's Arm.
Drop some ammo for a teammate.
Find the secret in The Armory.
Complete all Act 1 maps on Recruit difficulty or higher.
Complete Blue Dog Hollow.
Complete The Dark Before The Dawn.
Find the secret in The Dark Before the Dawn.
Complete Search & Rescue.
Defend the jukebox in Bar Room Blitz without it breaking.
Rescue a teammate from a cocoon.
Kill at least one of each non-boss Mutation.
Make a Breaker hurt itself.
Complete The Devil's Return.
Play 25 cards in a single match.
Kill a Snitch without it alerting the horde.
Heal a teammate.
Complete a mission without any players being incapacitated or killed.
Complete a map without any players on the team killing a single Ridden.
Complete a map without ever triggering a horde from Reekers, Birds, Snitches, or alarms.
Spend your first Supply Point.
Good luck out there, you're gunna need it.
Complete all Act 1 maps on Nightmare difficulty.
Complete all Act 2 maps on Nightmare difficulty.
Complete all Act 3 maps on Nightmare difficulty.
Complete Act 4 on Nightmare difficulty.
Kill 53,600 Ridden over your career.
Win a game in Swarm Mode.
Find the secret in The Devil's Return.
Find the secret in Search & Rescue.
Find the secret in Job 10:22.
Find the secret in Remnants.
Find the secret in The Abomination.
Find the Secret in Sunken Passages.
Find the Secret in Blood Stream.
Complete All Ridden Hives.
Get a kill with a Legendary Weapon.
Kill each of the Warped Ridden
Earn some Skull Totems.
Kill 10 Ridden with a Skull Totem.
Find the Secret in The Nursery.
Find the Secret in The Cut.
Find the Secret in Brood Lair.
Find the Secret in 300 Below.
Find the Secret in Caustic Cesspool.
Complete all Act 6 maps on Veteran difficulty or higher.
Set an enemy on fire with the Flamethrower, while also being on fire.
Complete all Act 6 maps on Recruit difficulty or higher.
Kill all variants of the Sentinel.
Complete all Act 6 maps on Nightmare difficulty or higher.
Complete all Act 6 maps on No Hope difficulty.
Find the Secret in Act 6.
Land a final blow on a Boss Mutation with the LAW.
Play Trial of the Worm for the first time.
Earn a score of at least 100,000 in Trial of the Worm.
Complete a map in Trial of the Worm with a total modifier of at least x20.
Defeat The Harbinger without using the LAW.
Blow up a Food Item with the LAW.