Finally get through the game. Got to admit that I didn't liked it as first, being very confused on what should be done and stuff like that, and died a few times because of it. (For the first round I didn't even know there is a mine half way through, I guess I was just thinking this was steam world dig) But once figured out what is happening, I was then finally enjoying what the game has to offer. What I especially like is the urge to heal your father or he dies. It really force the player to do stuff rather than playing around.
Now to the nitpicks. I feels like the mining was a bit too simple, it would really adds a layer of complexity to the game to spice up it a bit. Say, multiple ores each giving different gems, ores that require potions to mine, so on and so on. Potion crafting is a interesting mechanic and I really enjoy how it's the actual important part of the game. I ends up needing something to write down the combinations so that I can use that effectly. Not that I am complaining but it would be better if there is some sort of recipe once you successful make a potion. You could probably then make that system way complicated than what it is now and still don't overwhelm the player.
Anyway, I think you did a good job, especially given that it's just 4 days for you. Well done!