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