I remember playing this game some time ago, and I also remember enjoying it quite a lot. I looked it up, and apparently it was developed by Metropolis Software, a studio which is owned by CD Project Red since 2008. Since CD Project Red owns GOG as well, and Gorky 17, it's prequel is in the catalogue, I see no reason for this game and Gorky Zero: Beyond Honor not being available on GOG. Does anyone know, why they are missing?

Bump

While CD Projekt may own the devs of Gorky 17 if you check the Publisher:
http://www.gog.com/game/gorky_17
Its actually listed as TopWare rather than CD Projeck, compare with The Witcher:
http://www.gog.com/game/the_witcher
which IS a CD Proekt published game - its more about who owns and controls the publishing rights rather than who owns the dev studio, unfortunatly

Yeah, I guess you are right :(