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 $2M — a different platform, not this one.

Moonstone Island

Moonstone Island is a creature-collecting life-sim set in an open world with 100 islands to explore. Make friends, brew potions, collect Spirits, and test your strength in card-based encounters to complete your Alchemy training! Spend time on islands in the sky! Following your village's tradition, you must move to an island in the sky to complete your Alchemy training. Armed with a team of nature spirits, magical potions, and the support of your new friends, you'll explore ancient temples, dangerous dungeons, and hostile biomes to uncover the dark secret of Moonstone Island.        Befriend NPCs, become a member of the community, go on dates, and fall in love    Build a new home on any of the 100 islands in your procedurally generated world    Grow crops and flowers to brew potions and tame spirits    Customize and decorate your home to make it uniquely yours     Travel by balloon, broom, and glider through unique biomes to reach the outer edges of the world    Tame and befriend wild spirits to fight alongside you    Discover and explore dungeons to earn upgrades, collect loot and uncover secrets    Optimize your character with unique skills and upgrades    Craft dozens of items and vehicles to prepare for the treacherous wilderness