Issue about jagged lines that you can see below.
It is actually moving at that time in a left direction.
Below this is the idle state and no movement at all.
Quality settings maxed out.
This one is a free fall and jagged lines are much annoying.
I believe it has to do with TemporalAA. Try to use FXAA. The option is located in Project Settings, under Anti aliasing Method. TemporalAA is not good with fast moving objects 