Thanks so much! 😊
The limitations of the Game Boy hardware - while often a hindrance - certainly helped a bit in getting things done: Since the Game Boy screen has a resolution of only 160x144 pixels, the sprites can't be too big. And creating smaller sprites is a lot faster than creating larger sprites.
The shops don't update yet. I threw them together as quickly as I could in the last hour before the deadline. I'm going to completely overhaul them after the jam. I'll add a day-night-cycle and the shops will have new items each day. However, you can get (most of) the items from the screenshots from treasure chests during exploration.