i really want to love this game since its so cool but i think it it feels just a tiny bit to jank to fully enjoy. i think if you made, the rifle raycast instead of projectile (or just made the projectile really fast and raycasted between the past and present points of the projectile) or made the boss attack a little slower it would go a long way. i gotta say the visuals are truly awesome especially for a game jam and i think the vibe and atmosphere were done beautifully. i think with a little tweaking and polishing this would have a lot of potential, despite the fiew issues i mentioned this was one of the cooler experiences of the jam and the scope of the project is truly impressive. keep up the great work!!
edit: we went for a similar thing with the cards and i gotta say i like the way you implemented it more, super neat!