I really loved the snow, fog, and general atmosphere. I feel like some ambient winter sounds would have been really impactful, even without much gameplay to speak of.
I read your post-mortem, and I really agree with the first point. If you don't start with at least a loading screen, menu, game over screen in mind, these can be somewhat problematic to try to implement on top of a bunch of existing code. I experienced a bit of that with my entry as well.
The second point too. So important to figure out the process of releasing the game on itch way way before the deadline. Even if you have no gameplay at all, get it onto itch early.