“Never Let Go” is a mystery, but it’s often trying to be a scary movie to help engage viewers with film elements they’re more comfortable with. Screenwriters Kevin Coughlin and Ryan Grassby have a story to share about family issues and learned behavior, setting up a gothic study of survival focused on a mother struggling to protect her two young sons from an undefined evil in a potentially post-apocalyptic world. Director Alexandre Aja (“Piranha 3D,” “Crawl”) has the unfortunate task of pushing to make one kind of film while the writing is looking to develop another. The helmer gives the picture a nice boost of backwoods mood, and initial scenes of threat are capably handled, but “Never Let Go” starts to fall apart the longer it delays the inevitable, becoming a chore to sit through. Read the rest at Blu-ray.com