Enter “ Saturday Night Live ,” the sketch comedy variety show that launched a cultural revolution and the careers of Eddie Murphy, Will Ferrell, Kristen Wiig and Bill Murray, to name but a few of the hallowed actors who have worked their magic at Studio 8H, 30 Rockefeller Plaza.

Jason Reitman assembles a giant, game ensemble for Saturday Night, a SNL origin story that's a little too reverent and tidy.