Hi there, this thread I acknowledge is from a year ago but still hoping this may be seen; I am having the same issue of loading screen purgatory; even with deleting and redownloading the zip folder of the game I bought from the direct Short Hike website. I can click z to start and click again to hit continue then it's just the car driving with the loading dots at the bottom that never end.
If there's a known fix I would love some help, I was at 19 golden feathers and almost done with all the side quests and the main story, so I would really love it if there's a way to not toss out all the progress.