how to unlock characters on ww2 zombies?
['B.A.T. Agent: Kill a Treasurer Zombie. ... ', 'Survivalist: Get to Round 30 without purchasing perks. ... ', 'Hunter: Obtained Zombie Hunter part A — random Treasurer Zombie drop. ... ', 'Mountaineer: Survived 20 rounds without opening doors. ... ', 'B.A.T. Elite: ... ', 'Assassin: Defeat the Panzermorder by Round 12.']