If the game goes off‑screen or the sides extend past your monitor, you can fix it by changing the fullscreen mode in the registry.
Go to: Computer\HKEY_CURRENT_USER\Software\StepFurtherStudio\PTG
Find the value: Screenmanager Fullscreen mode_h3630240806
this number h3630240806 might look different on your system
Change it from 1 to 0.
- 0 = Exclusive Fullscreen (proper resolution change, fixes scaling)
- 1 = Borderless Fullscreen (stretches to desktop resolution, does NOT rescale the game)
- 2 = Windowed