Complex sentence: An extended film montage then begins, focusing on David running downhill (toward the camera), away from the sandpit, with flashbacks of the film's important events superimposed over a close-up of his face, including several scenes played backwards for surreal effect.
Split into simpler sentences: An extended film montage begins, focusing on David running downhill (toward the camera), away from the sandpit. Flashbacks of the film's important events are superimposed over a close-up on his face, including several scenes played backwards for surreal effect.