Undead Citadel achievements

Kill 100 undead enemies

Finish level "Tower" (10)

Finish level "Gates" (2)

Finish level "Runway" (5)

Finish level "Catacombs" (7)

Finish level "Entrance" (1)

Finish level "Bridge" (3)

Finish level "The Maze" (8)

Finish level "Graveyard" (6)

Finish level "Inner walls" (9)

Finish level "The wall" (4)

Survive for more than 10 waves in the Horde mode