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 $1.9M — a different platform, not this one.

Shelter 2

Follow a powerful Lynx through vast open landscapes. Give birth to your cubs, raise and strengthen them by mastering your skills for hunting prey. Explore the wild beauty of nature and do everything possible to prepare your family for the vicious entities dwelling on the cold tundra. Shelter 2 portraits a mother lynx and her life cycle, starting as a pregnant animal preparing her den for the coming litter, giving birth, and continuing in to a journey of parenthood where nurturing her cubs is paramount for survival. The more you feed the stronger you and your cubs will become, and failing to find food will lead to dire consequences. To avoid starvation there are many features to master, such as different types of movements, jumps and techniques for hunting prey. Besides finding food you must make sure to have a good den, see that your cubs drink water from nearby rivers, and make sure to call them close when they wander to far away. In Shelter 2 you get to play as a powerful predator – The Lynx. You can collect bone trophies of all the prey you kill. You can also collect rare items found in the wilderness. The world is a vast open nature which you can explore and return to. You will always have a base in center of the world – Your den.