An interesting premise can’t pick a lane in Peter Chelsom’s coming-of-age, sci-fi, mystery rom com. Gardner (Asa Butterfield), born and raised in secret in a Martian research facility, comes to Earth as a teenager. He meets his internet pen pal, a street-smart teenage girl named Tulsa (Britt Robertson), and the two of them steal a car and drive to California. They learn about life, love, family and in Gardner’s case, hamburgers. The film also offers a number of side plots — some melodramatic, some metabolic — featuring BD Wong, Gary Oldman and Carla Gugino. The main plot is insanely preposterous, but it might have worked if the story had taken a more focused and bittersweet bent. It must be lonely being the only boy on Mars, and a trip to Earth — where literally every other human lives — must be more meaningful and upsetting than this mish-mash suggests.