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