dialogue is scratchy and the camera movement is jerky and freezes. Playing on Windows 8 but the game is impossible to play as it is.

What kind of processor and graphics card do you have? Pegasus Prime will use the best resolution available, but if your graphics card is unable to maintain a smooth frame rate, try switching to Windowed mode by pressing ALT-ENTER and then setting your monitor to a lower resolution. You can also pre-set it to launch this way by editing the INI preferences file. There's more information about this at http://thejourneymanproject.com/presto/journeymanprime/support.html

You can also contact GOG Support.