Can y’all assist me?

My brother used to play this sport,that was portrait seen and the presence of this sport was a survival improve chess-like sport (as you possibly can see that the hexagons..srry for ass hexagons however yeah u kinda get it) the place you defeat these zombies and go to homes to loot sources and going again to camp/base to improve.Instructed my brother what the identify is and he absolutely forgotten it,And if anyone now's the secret pls reply✌️🥀♥️🥺