Hello. I really like whats going on here. So I wonder if I have a game in my steam library and GOG store have a same game can I add my steam game to the my GOG library? Thanks.

Currently, apart from Witcher, Witcher 2 and some retails games, you cannot normally reclaim games bought from other shops on GoG.

The "compatibility" part of Galaxy was about the possibility to play some GoG games online together with peoples who bought them on Steam. But AFAIK no information yet on how it will work technically.

But the reclaimable games will grow in numbers so probably it will be possible in the future (for publisher willing to ditch their DRM).

Thank you.