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 $920K — a different platform, not this one.

Sumerian Six

Sumerian Six follows the Enigma Squad, a team of commandos composed of the world’s greatest scientists who combine their skills to conduct secret missions in their fight against the Third Reich. Together, you seek to thwart ex-member Hans Kammler's nefarious plans involving a powerful, mystical substance named Geiststoff. Embark on a thrilling journey across multiple continents alongside allies such as the exiled chemist Rosa Reznick, Wojtek the Werebear, and the esoteric psychoanalyst Siegfried von Adelsberg. Dispose of your enemies by using each team member’s unique set of abilities inspired by their fields of expertise, and learn to master the art of chaining them together for devastating effects if you hope to be successful. As you delve deeper into the Nazi plot, you’ll encounter occult-scientific weapons and ancient Sumerian artifacts linked to Kammler's machinations. A grim future awaits you should the Nazis be victorious, so do your best to prevent that dark timeline from coming true in this real-time tactical stealth adventure. Demon Nazis Led by Hans Kammler, a former member of your Squad, the Nazis tap into the occult to create the ultimate Wunderwaffe. Face off against heavily armed, mutated, and supernaturally charged forces, and put your strategic abilities and dexterity to the ultimate test. Playful Violence Meets Super Science Sneak your way around Nazi strongholds and dispatch the ever-present watchmen in a variety of ways before taking on the more serious threats before you. Combine your team's dynamic powers in creative displays of tactical might. Travel the World Inspired by real places and events, Sumerian Six takes you on a journey through an alternate history where folk stories and conspiracy theories are as real as the Nazi threat.