It does run at 320x240. But with the current size of graphics to me it seems cramped.
So to fix it either I"
1. scale down 640x480
2. shrink down graphics / or have them redrawn ( problem is that the graphics are from hunt for gold, which i think minimum res was 800x600)
I put the resolution settings in a config file so I can switch back and forth between resolutions for testing. But the resolution only changes the viewabe camera area.