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 $12.8K — a different platform, not this one.

Oirbo

Assemble yourself in a hostile spacecraft where almost everything that moves is trying to get you. The reason ? Yours to discover! Explore, fight and learn your purpose in this galactic action-adventure.    Oirbo is a 2D action-platformer adventure that takes place on a huge spacecraft divided into interconnected areas. Search in every section for the pieces that make out the history of the journey and enhance your skills and components to get to new heights.  Explore a massive spaceship to find answers, but beware the army of robots that are coming for you; avoid them; fight them or simply outsmart them in this futuristic hand-drawn adventure in space!  Beautiful hand-drawn art  Classic platforming and combat system  Choose your own path to explore a monolithic spacecraft  Not a single line of human text to read!  Discover new skills and put them to the test on challenging platforming puzzles  Piece together a fragmented story from the past  Responsive controls with either keyboard or controller.  Dozens of enemies to fight and overcome  10 to 20 hours of gameplay  5 bosses to vanquish