Use the ThirteenAG Widescreen Fix to prevent the HUD from stretching and to enable high-definition resolutions.
If the game isn't in your preferred language, use the Language_setup.exe found in the game's installation directory. Mafia.GOG.rar
The original game was built for mouse/keyboard. While you can use a controller, it often requires external mapping software like Steam Input or DS4Windows to feel natural. Use the ThirteenAG Widescreen Fix to prevent the
Since you're looking at from GOG , keep in mind that this specific version is famous for having its original licensed music removed due to expired rights. Mafia.GOG.rar