I am writing a fictional story (could be considered science-fiction) about slightly primitive people. It is set in cold environment where a day cycle takes a whole year. Inspired by Antarctica, with the weather being more of Canada. The story also includes a cave network with groundwater heated by volcanic activity, and natural crystals that glow a soft blue light.
Most of it (other than glowing crystal) could happen in a natural environment such as Earth. Although perhaps would be more understandable in an environment such as a make believe world. My only concern in setting the story in a make believe world is that it seems to me, unless done very well, the story would feel unrealistic and be harder to get absorbed in.
Would this be more believable set on Earth or in another world?