Undead Citadel achievements

Finish level "Gates" (2)

Finish level "Graveyard" (6)

Finish level "The wall" (4)

Kill 100 undead enemies

Achieve all the achievements

Kill 1000 undead enemies

Survive for more than 30 waves in the Horde mode

Kill 3 enemies with a single explosive

Take an arrow fired by the enemy in mid-air

Freeze 100 enemies

Survive for more than 20 waves in the Horde mode

Kill 10 crows