This is a touchy point in the community cause some believe line battles made up most of the war, now on the other hand the 'Maryland campaign' is still early in the war
I've seen pictures/engravures where soldiers effectively took advantage of the terrain to have some form of cover or strategic advantage … that's is way different then slowly moving inline accross an open field.
About the game :
Like Leifr said it's hard to tell, for me it looks more like a startup video to get people interested in the development.