Hi insx, glad to see you are still keeping this forum alive.
I use Dosbox on the Pi. I ripped my original Timeshock cd, installed the contents on my computer and moved everything to the Pi (and added a startup script.)
When I played this version on my computer I saw the same choppy ball movement. But that was also through Dosbox so you may be right that it is an emulation artifact..not much to be done about that.
Btw: Lowering the resolution does not make it better and multiple balls at thesame time does not make it worse, so I figured it's not a performance issue.