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