Why a run should resolve, not loop
The most common mistake in physics-based short-form video is publishing a clip that simply stops. The balls are still bouncing when the video ends, which means there was never a reason to reach the end. Retention curves on that shape of clip fall away steadily from the first second and never recover.
A resolving run inverts this. An escape run has a final ring. A breaker run has a last pane of glass. A time trial has a countdown that either completes or does not. The viewer can see the ending approaching and has a reason to stay for it, and that anticipation is worth more than any amount of visual polish.
This is why the mode you choose matters more than the settings you apply. Spawner and trail runs are open-ended by nature and work best as ambient loops. Escape, breaker, spiral and ghost escape runs have a built-in conclusion and are the better starting point for anything you want watched to completion.