Here is the full list of all 42 Warhammer Age of Sigmar: Storm Ground achievements.
Equip a skill on a unit for the 1st time
Complete 1st Death Encounter
Complete a Realmgate Encounter
Complete a Stormvault Encounter
Level up a Base unit to Level 3
Level up an Elite unit to Level 4
Level up a Hero unit to Level 5
Defeat Death Boss (1st time)
Defeat Life Boss (1st time)
Defeat Metal Boss (1st time)
Slay 50 Base units in Campaign
Slay 25 Elite units in Campaign
Slay 10 Enemy Heroes (MP)
Destroy 3 Soul Prisons (MP)
Remove all Armour from 10 enemies (MP)
Use a Divine Act in Campaign
Send an Assassination target into the depths
Gather 20 Chests in Campaign
Summon an Endless Spell (MP)
Summon the Stardrake (MP)
Summon the Winged Nightmare (MP)
Summon the Great Unclean One (MP)
Collect 13 Lore Cards
Collect 5 Aethyr or Power from a Wellspring at once
Kill 5 units via displacement into hazards or chasms
Knock 10 units into other units.
Slay 5 enemies with the Purple Sun of Shyish
Kill 5 units with a single attack or ability
Win 1 match versus AI
Play 5 matches versus Friends or AI
Win 1 game in Automatch
Win 5 games in Automatch
Win 10 games in Automatch
Win 25 games in Automatch
Equip a Legendary item on a unit or hero
Collect all Stormcast units in Campaign
Collect all Nighthaunt units in Campaign
Collect all Maggotkin units in Campaign
Collect 10 Wargear and / or Skills in Automatch
Collect 10 Stormcast units in Automatch
Collect 10 Nighthaunt units in Automatch
Collect 10 Maggotkin units in Automatch