Rewind

public bool Rewind { get; set; }

using (Presentation presentation = new Presentation("demo.pptx"))
{
    // Get the effects sequence for the first slide
    ISequence effectsSequence = presentation.Slides[0].Timeline.MainSequence;

    // Get the first effect of main sequence.
    IEffect effect = effectsSequence[0];

    // Turn the effect Timing/Rewind on.
    effect.Timing.Rewind = true;
}