Joss Whedon’s Avengers: Age of Ultron (C) assembles all of the superheroes from the original hit but little of the wit for a flimsy follow-up. Lumbering, uninspired and overlong, the film now carries the burden of having to extend the franchise that’s now in spinoffs, on TV and cross-platform. It all seems like a perfunctory business exercise; attempts to elevate the excitement and the scale of the fight sequences just become lugubrious. Without a clear protagonist and with a metal villain whose intentions beyond destruction are unclear, the film limps to its inevitable box office triumph. One sequence with the heroes all trying to hoist Thor’s hammer captures the potential charm of this many greats in one comic movie; the rest is forced.