Here is the full list of all 26 Warhammer: Vermintide 2 achievements. It takes around 120-150 hours to unlock all of the achievements on Windows.
Complete Act 1
Complete Skittergate on Recruit
Complete Skittergate on Veteran
Complete Act 3
Salvage an item
Equip a Rare Item
Equip a Common Item
Equip an Exotic Item
Complete Prologue
Unlock 1st Talent point
Craft an Item
Complete Act 2
Complete Skittergate on Champion
Complete Skittergate on Legend
Reach level 30 with Kerillian
Reach level 30 with Saltzpyre
Reach level 30 with Kruber
Reach level 30 with Sienna
Reach level 30 with Bardin
Reach Level 30 with all characters
Unlock all Talent points for 1 career
Craft 50 items
Salvage 100 items
Equip Exotic items in every slot
Equip a Veteran Item
Complete a level as every Hero