Really cool game! There were a few things that threw me off when I first tried it - namely I first tried to take scrap to the furnace (I completely missed the arrows to the smelter lol). I also quenched my first ingot, having to heat it all the way from blue before forging it. It was fun figuring the precise order out. Because of my mistakes, my first score was pretty low.
All in all it was really fun! The minigames were a nice touch - it was truly frustrating when I was assembling a weapon but saw an ingot overheating on the furnace.
I also saw the bug where you could keep playing after the time ran out - as you suspected, I was in a minigame when the time expired. The score on the UI didn't go up even after delivering the weapon though.
-sam