In the Broadway adaptation, which opened on Thursday at the Winter Garden Theater, the famously souped-up DeLorean DMC, or a life-size replica thereof, is terrific — in some ways more exciting than the one in the movies because it does its tricks live. Well, partly live. The time-warping, plutonium-powered joy rides that shuttle young Marty McFly (Casey Likes) between 1985 and 1955 in the vehicle retrofitted by the eccentric Doc Brown (Roger Bart) are crafty illusions combining mechanical action, busy projections and a lot of distraction with fog, lights and sound. Alas, that also describes the rest of the show, directed by John Rando with Doc-like frenzy: mechanical, busy, distracting, foggy. Though large, it’s less a full-scale new work than a semi-operable souvenir.