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