I'm a bit speechless here. Every single thing in your game is absolutely polished. The design, the graphics, use of post processing, the sound. Great controls (I mean, I played enough of games in this jam to tell you getting the dash distance is NOT an easy task), great atmosphere (if you asked me yesterday I'd tell you, I'm bit over post-apo. but you proved me wrong). You even had dialogue scenes with cool character designs!
As I see it, this game has only one flaw, and it has to do with the theme. The "makeshift" in your game is only thematic, and not really gameplay based.
In the end, one question- will you be developing this further? Because I'd be interested in playing a full version if you do!
Over all- if this had more bosses- it would easily be the best game (at least so far for me). With just one boss... hell, it still may be! Definitely among the best!