Obviously legal issues prevented GOG from including the Risen 2 soundtrack. (I guess it was only officially included in a collector's edition? Google didn't find it on Amazon mp3 or iTunes, which is strange.)

But you can check it out on YouTube:

http://www.youtube.com/results?search_query=risen+2+soundtrack
http://www.youtube.com/watch?v=qzBRosZvLoA
http://www.youtube.com/watch?v=F4T9iNEPUX0&list=PLB09C6D4E52D1D7C2

Is there a way to extract the song files from the game files?