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 $227K — a different platform, not this one.

BLACKHOLE

BLACKHOLE is an award-winning hardcore platformer with over 15 hours of story-driven sci-fi comedy and gravity-twisting puzzles. BLACKHOLE includes the free Challenge Vault DLC. When the crew of the spaceship Endera is sucked into a black hole, it seems like the end. Fortunately, the ship crashes on Entity – an unidentified object resembling a planet. After the crash, the first member to wake up is the guy who makes coffee for the crew - you! There’s no one around and your only ally is Auriel, the ship’s computer’s sarcastic A.I. Together, you’ll need to come up with a plan to fix the spaceship, save the others and become heroes of planet Earth by closing the black hole once and for all. It won’t be an easy task, because the mysterious caves, lost cities, towering mountains and deep forests are full of tricky, gravity-defying puzzles and deadly traps. - More than 90 levels in 6 dimensions to explore - Hundreds of secrets to discover and puzzles to solve - A fully-voiced sci-fi comedy with a cool soundtrack - Pixel-perfect controls for both keyboard and gamepad BLACKHOLE: Challenge Vault: Take everything you have experienced to the next level! Enter the Challenge Vault, a special simulation for Endera agents, and participate with others in a secret training protocol. Select your favourite character and beat the records set by other players in this brand new online mode. For 15 weeks, you will get access to new exclusively designed levels full of gravity-twisting puzzles and fast-paced action. Be the fastest and become the King of the Vault in our online tournament mode. - Big tournament with other players - 15 new levels exclusively designed for speedrun - Play as Coffee Guy, Cpt. Jetsen, Selassie, House, Ati, Smusa, Nejfake or Skelet - Brand new soundtrack composed exclusively for Challenge Vault - New leaderboard system for “story” levels - The DLC is free for everyone!