The most recent installments in the “Superman” franchise—Zack Snyder’s diptych “Man of Steel” (2013) and “Batman v Superman: Dawn of Justice” (2016)—had hectic, howling, near-apocalyptic sense of tragedy, but James Gunn’s vision is “bright, chipper, and sentimental,” Richard Brody writes. “The world may be going to hell, but the writer and director James Gunn has graced it with a sunshine ‘Superman.‘ ” Gunn—who not only wrote and directed the new movie but is also a co-chairperson of DC Studios at Warner Bros.—applied the formula that served him so well with his three Marvel “Guardians of the Galaxy” movies to his début in the DC universe. Like those films, which established Gunn as an industry leader in the field of spectacular big-budget fantasy, “Superman” is a group movie in which the interactions of many characters, with their gibes and quips and whimsical bonhomie, decorate the churning action, offering catchy distractions but little substance.