Here is the full list of all 33 Undead Horde 2: Necropolis achievements.
Survive 2 minutes in the Necrodome.
Fully restore every building in Necropolis.
Reset your upgrade cards.
Craft an item with three affixes.
Conquer all levels in Darklands.
Conquer all levels in Citadel.
Reclaim the Necropolis Throne.
Kill the Archmage.
Enter Citadel.
Conquer all levels in Desert.
Conquer all levels in Winterlands.
Obtain 15 unique rune powers.
Dig up 10 buried treasures.
Assign 5 nobles to council seats.
Upgrade a unit building to level 3.
Include 5 different unit types in your horde.
Enter Desert.
Unlock 10 different unit types.
Slay the mythical Beast of Carmague.
Gain 100,000 gold.
Stop the elven ritual and kill the ancient fire elemental.
Complete all merchant's quests.
Destroy a Freezing Monolith.
Find a noble soul jar.
Die for the first time.
Enter Winterlands.
Reach Level 6.
Solve the puzzle in Forgotten Crypt.
Uncover 5 secrets.
Restore 10 buildings in Necropolis.
Acquire your first talent.
Claim Scavengers' Bog.
Enter Darklands.