The sun or moons? how are you gonna say anything about the sun or the moon, without knowing directions? "when the moons are kind of touching each other, walk left"? And if someone tells me to walk left at the big mountain, I'm gonna kill him, because Skyrim is largely made of mountains.
Besides, who knows what you might find in addition to that lost friend...
Quests aren't even usually part of FPS', was there quest markers in doom? In real life I would have a compass, or a map with everything marked on it. In real life I would have the ability to get someone to mark what is not marked on the map. I really don't give a [censored] about what else I find, because I'm not trying to find anything but my lost friend in your scenario. When I explore, I explore, and when I do quests I do quests. I absolutely hate this notion that being lost equals exploring. I don't need to be forced to explore, I like exploring, I hate being lost.