Hello! Thank you for your comment.
Regarding the collision of the flame it is intentional but I will change it; I made this choice because the "zombies" do not have a real AI but they just follow the player. Everything would have become too simple if the flame had hit more of a zombie at a time but this often causes problems in collision detection.
Anyway, as I told you, everything will be changed soon.
For the sound you gave me a nice idea and I will follow your advice.
Finally, as far as the background and lights are concerned, you're absolutely right but I didn’t even notice them. I will change these aspects and improve the scenario to make it more realistic.
Thanks again and if you have any suggestions please feel free to write to me.