Make sure you have wine installed at minimum 6.20 version (it was tested by me). Here is how to achieve this: latest wine installation
Make sure you have proprietary producer's graphic card drivers installed. For example for NVIDIA required version is minimum 410.93 (it and the newer were tested by me). Here is how to achieve this: NVIDIA GTX GeForce drivers installation
sudo apt install scummvm
env WINEPREFIX=~/.wine32-galador WINEARCH=win32 /opt/wine-staging/bin/winecfg
In a popup window in Applications tab select Windows 10 option.
Next switch to Graphics tab, check Virtual Desktop Emulation checkbox and
fill in your desktop's resolution in use, for example 1366x768.
cd [directory with game instalation files]
env WINEPREFIX=~/.wine32-galador WINEARCH=win32 /opt/wine-staging/bin/wine setup_galador_1.0_\(51319\).exe
mkdir ~/Games
cp -r ~/.wine32-galador/drive_c/GOG\ Games/Galador ~/Games/