No, there's no fog.... I just enter a couple of meters into the cave and it doesn't go on...
Somehow I can't take a screenshot right now...?? My screenshot program is hanging... will try later and add it ^^
When I walk into the cave, there is just a ~5m deep room of empty space.... (no floor) and a final wall. When I hit enter (pause) and then resume, I get into the cave, though xD
It's just that I'm can't automatically enter the cave, everything else works fine
I could send you my game slot, so you can reproduce ^^
I finally managed to take some screenshots and while doing so I realized, that I could wander through the mountain and exit through the rock xD: http://imgur.com/a/q1Jce using v1.0.4