In ‘Babylon,’ Brad Pitt and Margot Robbie share billing with poop, vomit and over-the-top spectacle

Margot Robbie plays aspiring actress Nellie LaRoy, who talks her way into a film producer’s hedonistic party in “Babylon.” (Paramount Pictures)

What a mess.

What a sprawling, grotesque, self-indulgent, wretched, occasionally mesmerizing but ultimately over-the-top mess we have in Damien Chazelle’s Hollywood epic “Babylon,” which one imagines was supposed to be a lurid and show-stopping and unvarnished celebration of the hedonistic madness that enveloped the movie business in the 1920s but comes across as a three-hour plus attack on our senses — a flashy, sometimes dazzling but curiously uninvolving and often nauseatingly gross spectacle.