Hey there! I had a problem of sound not playing in the game (I admit I extract the .sh rather than executing it and going through the installation process, but apart from creating a desktop shortcut that should make no difference; also, rather than using the start.sh script I directly execute the binary, did not think to test going through the starting script before solving the problem).

This is the first time I open a topic to share my own solution to a problem of mine, so if I'm doing it the wrong way, by putting the solution in a separate answer rather than in the same message starting the topic, tell me.

So, as I went through a library check

ldd game/Binaries/linux/UDKGame-Linux

I saw some libraries were loaded from a subfolder in the game path, despite them being provided by packages installed in my system. So, I deleted the files and the game loaded from my /usr/lib32 folder instead, and sound now works.

Libraries were libogg.so.0, libvorbis.so.0, libvorbisfile.so.3 and libSDL2-2.0.so.0, in folder game/Binaries/linux/lib

Hope this helps someone!

It is not possible for you to mark your own post as an answer to your question, unfortunately. While this is to prevent people from giving themselves the associated rep, there really ought to be a way to mark your own post without gaining rep, or unmark your original post as a question. Otherwise, it remains an unanswered question forever. Not that I expect gog to ever fix that issue. I suppose you might be able to get a mod to remove the question tag from your post.