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 $941.3K — a different platform, not this one.

FlatOut 2

Experience the drive of your life as you throw yourself around on and off the track causing fences to shatter, tyre walls explode, water tanks and barrels fly across the track into other cars. And if anyone, including you, gets caught up in a big smash sit back and watch as the driver gets catapulted through the windscreen in spectacular effect. With over 5000 destructible objects on each track and 40 deformable pieces on every car sparks are guaranteed to fly increasing the mayhem with every lap! 

 Featuring an enhanced version of the original's lauded physics engine and even faster driving track designs, FlatOut 2 also boasts a plethora of improvements, enhancements and additions to make this the definitive FlatOut experience. Twice as many vehicles, a more sophisticated career mode, additional race environments, double the number of tracks; twice as many mini-games along with many multiplayer modes (via LAN only) are just some of the exhaustive features that are included in FlatOut 2. 34 vehicles to wreck, 12 rag-doll mini games, 60 track combinations, and thousands and thousands of destructible objects. Enjoy the mayhem while listening to a slamming soundtrack from artists including Rob Zombie, Papa Roach, Fall Out Boy, Nickelback, Wolfmother and more! Race hard and collide with up to 6 of your friends online in the souped up car of your dreams.