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