I think the biome is just an overall progression of difficulty all around. The terrain is not that dissimilar to Mountains; you need to move carefully up and watch your stamina bar. Not being able to see is a pain and I think a slight buff would be helpful. Since I play solo, a wisplight that we could put on the bow of the ship would be really handy since it is almost impossible to take a boat through the mist.
But like Swamp or Mountains, altering the terrain to make things easier might work, though there doesn't seem like there is a great need since most things are teleportable and one deosn't need to go back and forth to a crypt or silver vein with all the metal.