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 $133.8K — a different platform, not this one.

Cathedral

Wake up in a world with no recollection of how you got there. A world full of secrets, hidden rooms, dungeons and towns. Cathedral features a vast world, meant for exploring! Make your way through more than 600 rooms, and unravel the secrets of your past by finding the five elemental orbs. The orbs, placed in ancient times by the demi-god known only as Ardur, is protected by five fearsome guardians. Make your way through their dungeons, meet them head-on in combat, and see if you can best them! Feature list: Single player adventure game A large world to explore, filled with secrets Challenging boss fights A map system that makes exploring and backtracking the world fun Lots of varying puzzles, areas and enemies Awesome 8-bit music, made in Famitracker Many hours of gameplay