to put it in 1 sentence... this game is the closest one you get for a L4D type kinde of zombie game.
its a tps coop objective based zombie game with each character you choose has a different ability/role and there's no loading between maps(?)
at first you will start inside of a building then as the mission progress you will head outside to the "open world" map to go to the next objective.
its still need a lot optimization especially before a boss or a horde is coming...
content wise(skin, char customization,etc)... well its still an early beta(or even alpha?) so there's not much of it
overall this is one of the best actual coop zombie game
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