This much-revised comedy by Terrrence McNally, which is breaking box office records on Broadway, has a stellar cast including Nathan Lane, Matthew Broderick, Stockard Channing, Megan Mullally, F. Murray Abraham and Rupert Grint (from Harry Potter films), plus promising newcomer Micah Stock. Lane and Channing are at the top of their form, rattling off a nonstop series of bitchy zingers, many of them theatrical insider jokes that flatter the audience by making them feel in the know. Abraham, as an acerbic critic, reveals a manic comic side that I never knew he had. Mullally was out so I can’t comment on her; understudy Isabel Keating seemed flightier than necessary. Rupert Grint, as a hotshot British director who claims to crave failure, has to cope with a poorly written role and a hideous costume. Stock, who resembles a young Jim Parsons, holds his own in a long, hilarious scene with Lane. And then there’s Matthew Broderick as the author of the play whose opening night is being celebrated. He copes reasonably well with difficult material in Act One — a lecture on the depressing state of Broadway theater and a prayer for those involved in the business — but seems to retreat into a shell of blandness in Act Two. The fun is greatly abetted by an over-the-top set design by Scott Pask and hilarious costumes, including the outerwear of unseen celebrities from other Broadway shows, by Ann Roth. Director Jack O’Brien occasionally lets the pace lag. The wisp of a plot is about the anxieties of waiting for reviews on opening night, a somewhat dated concept in the age of instantly accessible reviews on newspapers’ digital sites. The second act fizzles more than it fizzes. McNally would have done well to follow one of the theatrical trends he deplores in the Act One lecture — 90-minute plays without an intermission. A string of one-liners, no matter how funny, does not stay fresh for two hours and forty minutes. It’s too much of a good thing.