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

Tumblestone

Tumblestone is the first original action-puzzle game of the past fifteen years. Race your friends in multiplayer or challenge yourself in story mode. Solve progressively more difficult and creative puzzles, help a sausage make friends, and find out what happened to the Tumblecrown.   Key Features   Competitive local multiplayer : Tumblestone's intense puzzle-solving action will turn playing "just a few more rounds" with friends into a late-night Tumblestone marathon. Local multiplayer : Up to four players on a single computer. Bots : Have an open slot? Play against the computer. But can anyone withstand the punishing Nightmare bot? Story mode : The 40 hour story campaign will test your puzzle-solving prowess. Featuring 10 gameplay modifiers, challenge puzzles, and boss battles. Arcade modes : Kick back and relax with the casual Marathon mode, scratch an intellectual itch with the Infinipuzzle mode, or get your blood pumping with the fast-paced Heartbeat mode. Quests : Hundreds of unique quests to complete. Stats : Rank up, then compare how you stack up against your friends. Personalization : Choose from a dozen unique characters and environments.