Thanks for enjoying the game. You are right I added that light depletion mechanic to create suspense. The flashlight stays at a low light level once you can no longer find more batteries. The game does not stop, you just have to play the rest of the game with dim light. The reason why I let the flashlight not run out ever is so the player always has a tool to help navigate around the base. The flashlight in the first version 1.0 of the game had an infinite amount of time with normal light level you could use.