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