hey Aliviessa! Thanks for playing my game, it’s the first “complete” working game I managed to finish for the jam, so I’m glad you enjoyed it :)
as for the refinery, you need to mine an iron vein first to obtain some iron. They look like gold veins, but white. then move close to the refinery and press E which will convert them into iron rocks which you use with the right mouse button.
also, when you say larger resolution, do you mean larger window size?