I am so incredibly happy to see another developer submitting an NTR themed game! This has not happened in the 5 years I've been participating in Strawberry Jams! There have been a few NTR-adjacent submissions over the years, but nothing explicitly focused on that theme.
The demo does a good job of showing the core mechanics and tone of the story. I like how the split party mechanic is implemented, though I would like a bit more control over it at times since my pairs ended up getting separated the same way too many times. There is a bit too much backtracking, I suggest always putting the missing characters in an area that isn't too far away but hasn't been explored yet which will incentivize exploration. You can also give a direction clue on the map to suggest where players should start searching. The map should indicate places where you got swept away by a snowstorm so that players won't have to rely too much on our poor memory. There is a visual bug where the map can be generated in a way that it runs off of the screen.
The music track fits the atmosphere, and the sprites are pleasant. Seeing the party visually following the player always feels good to me in RPG games. I like how the weather changes in each area, it's a flavorful little detail. The dialogue is fairly brief, but I got a good sense of each character. Self-insert protagonists in NTR games are common, so having him be renamable is a perfectly valid choice, but I think he should have a default name that isn't "Player". The menus don't do much yet, but I always liked them in NTR games as a way to tease a bit about what's happening with your companions.
I hope that you continue working on this project. You've definitely got me interested in seeing more!