Lundeen noted that in an early, much darker version of the game's lighting system, "Playtesters weren't able to see zombie silhouettes in the midground and background. Because of this, they were repeatedly getting mobbed." "While sudden zombie attacks were inarguably scary, they were also frustrating--players weren't being given the information they needed to react," said Lundeen. "They wanted that 'Here they come!' moment, and we weren't giving it to them. The solution? Light-colored fog."

"While not as realistic-looking as actual fog in some settings, it meant playtesters could see attackers in the distance. Once they were able to anticipate attacks, playtesters started to have a much better time."