I got the  option to choose whether I explore the mountains or the sandstorm, so I chose the snowy mountains, the problem is the only thing I can do there is fight yetis. Is that all there is to the snowy mountains or is there something else I can do? Can I also get back to the previous map?

yeah me too, i just play in 1 day and stuck in map snowy mountain, mybe in v. 2.1 get another story

i think you should to read this https://fd-caro.itch.io/tavern-of-spear/devlog/330337/v020c-update-log

How do you get the option to choose?