TRY DIFFERENT GRAPHICS MODES:
Please go to the game installation folder:
- If the game was installed via Galaxy, please select the game in GOG Galaxy, click on More -> Other -> Graphics Mode Setup
- If the game was installed via offline installer, then you will have to manually navigate to the game installation folder, by default it's:
C:\GOG Games\game-title\
Once in there find and run Dosbox Configurator.
In Graphics Mode Setup tool please select:
Graphics Mode: OpenGL
Fullscreen: Unchecked
Go to Advanced Options.
Windowed Mode: Select 1280x720 or resolution closer to your display resolution.
Press Save and close. Now try to run the game.
If this will not help, then please try changing the Graphics Mode, from OpenGL to other options.
EXPERIMENT WITH DOSBOX'S SPEED IN-GAME
Try manually tuning DOSBox's cycle setting, to see if there is a setting that works best for your system.
To do this, press Ctrl+F11 to decrease, and Ctrl+F12 to increase the setting.