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 $2.5M — a different platform, not this one.

Endling - Extinction is Forever

Will a mother fox manage to keep its little cubs alive? Experience a world ravaged by mankind through the eyes of the last fox on Earth in this eco-conscious adventure. Discover the destructive force of the human race, like it, day after day corrupts, pollutes, and exploits the most precious and valuable resources of the natural environments. Explore various 3D side-scrolling areas and defend your tiny furballs, feed them, watch them grow up, notice their unique personalities and fears, and most importantly, help them to survive. Use the cover of night to stealthily guide your litter towards a safer place. Spend the day resting in an improvised shelter and plan your next movement carefully since it could be the last for you and your pups. Features: Explore devastated environments based on real current issues. Hunt other animals to feed your cubs and avoid becoming the prey. Put your survival instinct to the test and get involved in emotionally taxing decisions. Find new shelters to be safe from natural and unnatural threats Care for your kits, feed them, and teach them new skills to make them less vulnerable. Survive. https://items.gog.com/endling_extinction_is_forever/Bafta.png