Seems pretty interesting, but I didn't think to check the time for my 2nd fledgeling, assuming it'd be 10 seconds, but it was higher so I was forced to fully restart, which is a killer for me
Maybe just removing your scavenged materials, so at least you retain your upgrades? Or maybe adding an extra icon if its cost would exceed your total capacity (or if you're feeling nice, your current amount)
Otherwise the sound design was nice, and the basic premise was pretty neat!