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