Many of us are old and have early bedtimes (and/or live in Europe). I would say that the biggest readon that it looks odd is that your mountains are single, straight strokes. Real mountains have a more dendritic pattern that has little segments that don't align, but are end-to-end.

You don't have a scale on the map, so it's hard to say exactly how the mountains should appear, but that style is generally fairly local. I really recommend paying a visit to Google Maps and entering terms like "Alps", "Rocky Mountains", "Andes", "Himalaya", or even "Panamint Range". Those are all good examples of mountain ranges that have a nice, visible structure.