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.
Reach level 30 with Saltzpyre
Reach Level 30 with all characters
Complete Skittergate on Legend
Reach level 30 with Sienna
Reach level 30 with Bardin
Reach level 30 with Kruber
Equip a Veteran Item
Complete Skittergate on Champion
Reach level 30 with Kerillian
Equip Exotic items in every slot
Unlock all Talent points for 1 career
Complete Skittergate on Veteran
Craft 50 items
Complete Skittergate on Recruit
Complete Act 3
Equip an Exotic Item
Complete Act 2
Complete Act 1
Salvage 100 items
Equip a Rare Item
Craft an Item
Unlock 1st Talent point
Complete a level as every Hero
Salvage an item
Equip a Common Item
Complete Prologue