I had an issue with this because I recall watching that initial sketch shortly after its broadcast in 1975, and it didn't strike me as amusing. That feeling carried through the entire film, which presents events unfolding during the ninety minutes leading up to the show’s debut, centered on creative producer Lorne Michaels (Gabrielle Labelle). The program was far from prepared, with enough material for three hours intended to fill that ninety-minute slot. His key performers—George Carlin (Matthew Rhys) —felt the whole project was worthless, while John Belushi (Matt Wood) and Chevy Chase (Corey Michael Smith) appeared to dislike each other intensely. Simultaneously, network executive Dave Tebet (Willem Defoe) created a tense atmosphere with that type of overly encouraging expression a soccer coach displays before being dismissed, and Andy Kaufman’s (Nicholas Braun) presence, along with a llama and some bricks, didn't inspire much confidence in its eventual broadcast. What follows might have been the chaotic, difficult creation of an American landmark, but for viewers outside the United States, this style of comedy feels dated, and LaBelle’s slight resemblance to Dudley Moore only emphasizes how eager this country was to move beyond the strict censors (Catherine Curtin) who seemed to believe a golden shower was something you'd see from Disney. It aims to combine various forms of innovative comedy, including an unusually long performance of Janis Ian singing “At Seventeen,” as a way to establish a new approach for late-night television; however, that doesn’t make it particularly enjoyable or informative. It’s acceptable to view once, but if this show isn't already ingrained in your mind, I doubt this movie will alter that.

Source on TMDB