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