First, I'd like to say that this is a very charming game. It took me longer than I'd like to admit to figure out how to go about handling the puzzles, but once I did it was enjoyable.
Also, I came up with a way to make Unity not lose save data when you post updates to your games. This describes how to do it if you're storing the save data in PlayerPrefs
https://3p0ch.newgrounds.com/news/post/1086279
and this describes a different way of doing it that's more flexible but not with the same built-in easiness of PlayerPrefs (it was intended to allow multiple game devs to collaborate on a multi-game project, but can be (and has been) used for stand-alone Unity games).
https://3p0ch.newgrounds.com/news/post/1099579
If you incorporate either of those into the game now, it will wipe everyone's progress for that update, but then will keep it for any future updates. For any future games if you use either of them from the outset then there won't be any save data loss with updates.