cool game, i think an add on like these would be cool (someone might have written some of these since ive only skimmed through the suggestions):
-pickaxe? maybe for mining and smelting you own ore?
-smelter ^^ turn your raw mined ores into ingots. ( i think that would add abit depth to the game)
-more weapons varieties like armor, accessories like rings, etc
-shop expansion pls! my stuff is so messy since its super crowded in there >.<
-haggling ability (get in extra moolah from what you're selling!)
-special orders (something like "i'd like a TIN dagger!") or something along those lines
-rare ores/ingots that you cant purchase but have to mine by yourself? maybe crystal ingots :D
-crafting expertise. maybe at the start even your copper weapons arent the best but the more you make a certain thing the better quality it is and its more expensive?
thats all i can think of right now. hope anyone finds it interesting >.>