I don't know, I just expected more. Fallout 3 GOTY look pretty well for its age. If you play Fallout 4 right after, you could become a little disapointed. Some parts of the inventory have been altered and the Pipboy received additional animation, which make using it worse than in Fallout 3. I'am only at the beginning in F4, I will continue as I progress in game.
Adding d3d9.dll will make it work, but it's a little disappointing that GoG is not adding this fix by default. GOTY contains all the DLCs but if you are searching for more "entertainment", I recommend the common mod-sites.
