This runs fine on my Mac.
When playing without fog-of-war disabled, it incorrectly computes which part of the map to draw (although water and objects are drawn).
Its always the right side that is not drawn, and the amount it is not drawn depends on how far you scroll.
When you are on the right side of the map, the ground is drawn, but there is 'popping' of objects and shadows on the rightmost edge of the screen when you scroll.
screenshot: