From the release:
Poland in Flames is a historical campaign book containing 70 scenarios and 16 operations taking place during the invasion of Poland in September 1939.
Players will be able to play battles and operations through the point of view of Polish, German, Soviet and Slovak armies.
The book also includes historical background about each battle and operation, historical background on important commanders and decisions, maps showing troop movements and mini maps of Poland so that players can get a general idea of the geographical location where the battle is fought.
The book is a free to download resource meant to be used with my September Campaign v.2 OoB book written for Flames of War and released last year.