This was a good solid trade sim! I loved the art, music, and overall aesthetic of the game.
The music was very very loud. I suggest while testing to pull up some kind of software that can monitor your audio levels independent of your system volume slider (like OBS). Ideally, the real time audio peaks shouldn't push against the limits of the monitor. I tend to like setting the limit at -5dB and keep the average around -10dB.
I also found an odd bug, that would allow the player to smuggle the item from the shop somehow. I was able to do it twice by accident, but wasn't able to repeat it. It seemed like if I attempted to buy something I didn't have money for and then left the store; when I revisit the store, the item would magically be in my inventory.
The upgrade menu also wasn't very clear on where to click to get the upgrades. Having the cost button set apart with a background or other bordering effect would bring more attention to it being a button rather than simply text.