Asking on Steam, they said that DRM don't allow to recognize a GOG game, should be installed on the stupid Steam apps folder, which I never liked (main cause of that if a game is on GOG, I prefer to buy on GOG first).

But test the achievements on Steam, I've installed Kingdom Rush from Steam, and imported on GOG, which works perfectly. The problem is that they don't run at the same time, even when they are the same game! when I launch the game on GOG, does not counts on Steam playing time, and vice-versa.

1. Is there a way to count hours in both at the same time?

2. The most important: Could be problems recognizing all my Steam games? I mean, install first on Steam, and recognize all in GOG? (when purchased on both).

The last question is related to that I saw many new files on the Steam folder. I want to know if that may cause problems to GOG or Steam games. (Disappear of saved games, cloud problems, corrupting data files, etc).