The first thing I noticed was how many areas are using fog at least in some way.
You can right click an image and open it in a new tab for a full size version. I compiled a series of screenshots to highlight the differences for several areas. While some areas in my opinion look flat out better without the fog, others arguably look weird or at least very different. Most notably, it has a big influence on how levels are lit. However, unlike for example Wolfentein: The Old Blood, where the fog was used rather conservatively, the levels in New Colossus were deliberately designed with the fog in mind. As with the head bobbing, you can use a corresponding toggle binding to switch the effect on or off from within the game.
As in the previous games, there is indeed a way to stop rendering the fog, which I included as an option in the new version v0.2 of the mod. Since the initial release of the New Colossus Tweaker for Wolfenstein II, I was asked by a few people if there was a way to disable the rendering of the fog, which is prevalent in many levels throughout the game.
