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