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 $739 — a different platform, not this one.
Volley Pals
Volley Pals is an adrenaline-packed modern style arcade volleyball game with different mechanics in each of its levels. We designed it as a local multiplayer party game that supports up to 4 people. Volley Pals is exactly the game you’re looking for if you want to be on the edge of your seat with friends, family, or anyone you can spend some super-fun time with. Gameplay Simplified arcade volleyball where you hit the ball and pass it to your opponent's field. However in Volley Pals, you can also do many other interesting things, which may not be welcomed in classic volleyball. Including but not limited to: invading your opponent’s area, using your opponent's service before they do, increasing the height of the net, playing rock/paper/scissors, and various other things that can be seen in the trailer. Modern arcade-style action Play against up to 4-player local multiplayer or AI Various crazy levels with different themes and mechanics A special level dedicated to customizing your own rules and preferences with a wide range of options Original and cute characters to choose from Stylish 2D cartoon graphics Playing options range from 1v1 or 1v2 to 2v2, with any number being AI or real players, so playing volleyball never gets boring! On top of that, with each level the gameplay gets crazier as a different mechanic is introduced, and it’s up to you to master it and play it to your advantage. All levels are designed with a unique theme that gets you excited for what is coming next! Enjoy every second with original and cute 2D-style characters to choose from, each with likable characteristics, topped off with beautiful music to get you immersed. You can even customize your own level to fit your tastes perfectly, a wonderful addition to the already delightful levels!