I like your idea here, but unfortunately I don't your game is very fun to play. The repetitive music is going to make me go crazy, and the core gameplay loop is a little monotanous. I like the idea of material prices changing as you sell them, but everything is very dark, and if you get so much as two blocks deep, it's impossible to climb out. This possibly could be remedied by having be balanced so that stamina is easier to buy, but that's up to you. Overall, not bad for a first game jam. Hopefully you'll go back to the drawing board on this and make something even better.