This is a nice game that really ties well into the theme. It is well rounded and I don't feel it has any loose ends.
I liked the core loop is simple but has depth. The game has a lot of things to take into account and I can see the player being overwhelmed by all of it all at once, however the tutorial gives the player the info progressively in a really smart way. I loved that.
I liked how different the salvaging feels the deeper you go with the different background, the sea creatures, etc.
I think maaaybe the only aspect I would make a suggestion on is the assets: The visuals are good, don't get me wrong, however I think it could be more cohesive. Some of the objects or buildings have a pixel art style, and others have more of a flat simple style.
Great job, I liked your game and I think it is one of the most complete I have played from the submissions :)