No revenue estimate for GOG — its rating/review counts don't calibrate to sales the way Steam's do. Reviews and prices only.

Schein

Schein is an award-winning, puzzle platformer that tells the story of a father who enters a mystical swamp in desperate search of his son. As he becomes enveloped in darkness and begins to lose hope, a wisp appears, offering him guidance and her magical power: a light that reveals hidden worlds. Use your wits and light to conquer mind-bending puzzles and defeat deadly beasts. Can you save your son in what’s possibly the trickiest platformer you’ve played?