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 $2.9M — a different platform, not this one.

Sudden Strike 4

Sudden Strike 4 sends you off on three extensive campaigns set amongst the battlefields of World War II .   Commanding the Allied, German or Soviet troops , you will lead over 100 different units into battle; like the German bomber Heinkel He111 , the Russian T-34 tank, the British Hawker Typhoon fighter plane and the notorious German Panzerkampfwagen VI "Tiger" .     In a first for the Sudden Strike series, you can now choose from one of nine individual commanders , such as George Patton or Bernard Montgomery , who will each allow for different approaches to combat and boast unique abilities .     Prove your strategic expertise in over 20 demanding singleplayer scenarios  and the challenge-focused skirmish mode .     Exploit the weak spots of tanks, set up an ambush , occupy buildings with infantry, outmaneuver the enemy with clever positioning or unleash devastating air strikes – how you approach each mission is up to you!     Optional „Pause & Play“ for more tactical depth