I encountered a problem where my character walks through some zombies without getting killed. And there's one with a metal hat that I cannot kill with the rifle.
Thanks for reporting!
Ore Miner 2 is my submission for a 5 days game jam and is no longer in active development, it received a bug fixing update after it and it should be stable enough to be played without too many annoying disruptions.
I added these bugs to my todo list, but I can not promise an update.