Well, pretty straight forward game. Now, I didn't noticed any major problems here. My only regret is that the game is so SO short, 3 Prosperity points are WAY too low of an objective. You could have let the player decide at the beginning.
Outside of that, there is one thing I'd like to address. Something weird I couldn't replicate for now.
I tried to build something (don't remember if it's a farm or a house), but the game told me I lacked ores, despite the fact I had enough. I had to get some more ore so finally the game let me to build what I wanted.
I started a new game to try out, but I didn't encountered that problem again at the moment.
Also, it's sad to say, but there is multiple save spots, but everything saves on the first one without letting a choice to the player. If I could have saved where I wanted, I could probably have sent you a save file of that bugged game, but because I started a new game to investigate it, it is no longer possible.
Minor detail, but the overworld sprite of the brother doesn't exactly fit his face sprite. So out of curiosity, I am asking: why making this choice?
Anyway, I wish you good luck with the game jam and your projects overall! Had some fun playing it - but mostly got disappointed by how short it was...