Here is the full list of all 21 Necromancer Returns achievements.
Win 40 battles.
Put artifacts on the hero.
Deal 15000 of physical damage.
Deal 5000 of magical damage.
Lose 2000 of health.
Deal 5000 of physical damage.
Win 20 battles.
Spend 200 of mana.
Win in 5 battles.
Complete Tutorial.
Heal 1000 of health.
Spend 10000 gold.
Summon 5 skeletons.
Resurrect after death.
Use Vampirism spell 5 times.
Use units’ abilities 20 times.
Learn all skills.
Upgrade all units.
Complete all quests.
Complete campaign mode.
Win in 5 battles in the mode of "Survival"