Wolfszorn: I like the GOG client and I know it's beta, I expect bugs. But this isn't a bug its a coding mistake. You can reproduce it at any time. And it's not something that happens in special circumstance, that's what frustrates me.
Wolfszorn, I'm very sorry to hear about your problem, however I cannot reproduce this issue as you explain it. To be more precise, here are the steps I've just taken seconds ago:
1. Installed the Client to the default path of C:\Program Files (x86)\GalaxyClient. It updated to 1.0.5.14.
2. Installed multiple games using the Client to C:\Program Files (x86)\GalaxyClient\Games (as you can see the folder is located within the Client installation folder)
3. Uninstalled the Client using default uninstaller available via Control Panel
The result was that every single installed game remained untouched in the C:\Program Files (x86)\GalaxyClient\Games.
Do you maybe have any cleaning software that assists app uninstallations that could have caused this? The other option would be that somehow your Galaxy installation were not updated (although this would be tough as Client updates are not optional).