Adding more atmosphere with fog texture and particles

It's kind of subtle and hard to see with the video compression, but I've tried to make the fog in Fist of the Forgotten look more volumetric and textured. With a shader, I've projected a Perlin noise texture at a couple depths to give the illusion of volumetric fog (but without the cost so the game can run fast on low end hardware). Also added some particles to give a better sense of motion and more atmosphere.