Hearts of Iron IV (HoI4) is the long awaited (seriously guys, seven years?) follow up to Paradox’s Hearts of Iron 3 (HoI3). HoI3 is a grand strategy game in which you can take control of any nation in the world from 1936 to 1948 and try to guide them through, or away from, World War II. You control everything from the armed forces, industrial production and research through to diplomacy and politics. HoI4 is more of the same, but with what might seem like minor changes, at least to the uninitiated.