No revenue estimate for GOG — its rating/review counts don't calibrate to sales the way Steam's do. The Steam version is estimated at $604.8K — a different platform, not this one.

Darkest Hour: A Hearts of Iron Game

Developed by a team of experienced modders from the Paradox forum, Darkest Hour is a stand-alone Hearts of Iron game. The game features a mixture of short and in-depth campaigns set across the darkest chapters of the 20th century. Play from the outbreak of the Great War up until the onset of the Cold War. Darkest Hour will introduce a new artificial intelligence that is now able to react to hundreds of different situations simultaneously. It implements a dynamic diplomatic system that will allow the player to have a real impact on the course of history. Short and grand campaigns allow players to experience the darkest hours of the 20th century, from the Great War to the onset of the Cold War New map, redesigned to offer greater detail as well as strategic and tactical opportunities Dynamic diplomatic system giving the player greater influence on the course of events New artificial intelligence capable of reacting to hundreds of different situations