I have so many ideas, and I think I would be good at having TONS of ideas even if they all aren't the best, but I have not the slightest clue how to code or program. Instead, here are some Ideas I think would be cool for the game:
1. Make a combat feature where you could go out and kill things with the weapons you make so you can get coins and every once in a while a random part.
2. Make it so the weapon making system is not so strict, such as being able to design your weapons with cool unlockable stensils or adding more parts for more variety, getting more money if the weapon and parts look cool together.
3. OH MY GOD make it sooo much easier to get money. no offense, but what were you thinking by making the first metal upgrade cost 490$ MORE THAN THE FIRST ONE. Also, I think it would be better to lower the prices of everything by A LOT than to just give more money.
4. Have more of a shop selection, so you can even buy cool upgrades, like making the water bucket get lower and get refilled by rain, but you can buy a well that connects to the bucket so it constantly reflills the bucket, or a house upgrade that makes it bigger, be able to buy more storage boxes, maybe even buy little people that will do work for you like put ingots on the forge or give a just made weapon to the customer.
5. Add a feature where you start out with a copper axe, hammer, and pickaxe. Through the game, get more and more materials and money to upgrade those into higher levels, using the axe to chop down trees to clear them up, or get materials like wood and leaves and such to make your own parts, and have buying them straight out as just a little side feature that is and easier option if you have the money to. Use the pick axe to break rocks that give you your ores for smelting, also buying them as a side feature. Finally, use the hammer as it is used now.
6. Have multiple shop systems, so you can go around and go to other people's shops to get materials instead of from your home, like if there is no stone with the material you need lying around, you can travel to the local shop for metal and buy it. Or get parts from the hardware store.
Those were all my ideas I I have now. Hope my spelling wasn't bad, I have a broken keyboard to keys are delayed and mess up and such.