What do you think???

Hi, writing a short novel and just finished the preface. I wanted to know what you think, its only the first draft so it's not very good, but hopefully i can improve it. Constructive criticism welcome!!! Thank you and here you go:

Stacy began to run faster and harder than ever before, because this times her life was on the line. The forest grew thicker the further she ran, until the sky was barely visible, but the moon still shone down at her in the distance, like a light at the end of a tunnel. Branches clawed at her face and arms, pulling her back, the muddy floor made running difficult, though she carried on. It was as if the forest was against her, making escapeing even harder. She knew that it wasn’t far behind her, but she dared not look back, the thought of facing that thing again sent shivers down her spine. Still running, Stacy began to slow down as exhaustion caught up with, the deafening drum of her heart increased with every step. Something rustled in the tree tops above her, there was no time for her to look up, no time for her eyes to widen in disbelief, or to let out one last gasping breath. In a second she had been thrown to the ground, and had slipped into eternal darkness.