For a time travel movie to work, it doesn’t have to offer a big idea, but speed is appreciated to help digest the particulars of this type of science fiction. Math and science is often most effective with some passion behind it, but “Curvature” doesn’t trust the value of excitement. Brian DeLeeuw has scripted a small-scale mind-bender, but he’s often stuck searching for emotional resonance with a story that seems built for exploitation interests. “Curvature” is dull, requiring a director who’s dedicated to the essentials of cinematic pursuit, but helmer Diego Hallivis seems overwhelmed here, trying to preserve DeLeeuw’s characterization while delivering limp action. The basics of time-leaping and broken hearts are here, but the production doesn’t come alive, weakening a passable detective story.  Read the rest at Blu-ray.com