Sounds like the Game Jam was a success for you - and that's all that really matters - especially after some difficulties with the team. I think you did well under the circumstances. My feedback was not intended to be harsh, but constructive. Of course take it all as just my opinion - I am not an expert by any stretch of the imagination.
My main point was that when under limitations, I think it is just as important what you decided to leave out as what you put into the game. IMO, a well executed small game requires all elements to reinforce the core of the game, whether that be a mechanic, theme, or experience. You did achieve this - big tick - but, the core mechanic reinforced by your design was mining rather than salvage as you stated was your initial intention.
This change from conception to execution happens all the time, even for AAA games. It can be due to losing focus on the core (which is often a negative) or sometimes the designer discovers a better core as they iterate the design (which can be a positive). A good example of this is Horizon Zero Dawn (there is a great NoClip documentary on Youtube about it). I leave it to you to self-reflect on your experience and I hope this feedback will help you in future Jams.