If slapstick isn't your thing, then turn around now. This farce is not for you. But if goofiness makes you giggle, then "The Play That Goes Wrong" may leave you gasping for breath. This British import started as a play above a London pub, created by recent graduates of the London Academy of Music & Dramatic Art. Eventually, it moved to the West End where it was cheered on by audiences. And now, it's landed on Broadway.  It's a play-within-a-play that's being staged by the Cornley University Drama Society. When we're first introduced to the "director" of the Agatha Christie-like mystery set in a 1920s mansion, he's happy because to be working with a larger budget which allows for a larger space and more actors. "We will certainly be able to outshine our rather underfunded production of Roald Dahl's 'James and the...Peach,'" he says. "Or last Christmas's 'The Lion and the Wardrobe.' Or indeed our summer musical, 'Cat.'" What follows is a symphony of silliness, with the set falling apart piece by piece, often conking an actor's head in the process. It starts off funny and just gets funnier.  I have some quibbles. Cutting a good 15 minutes or so (as well as the intermission) would make it swifter. And there's a bit too much cat-fighting for my taste.  But otherwise, this play is just good fun — that literally brings down the house.   The Play That Goes Wrong By Henry Lewis, Jonathan Sayer and Henry Shields; directed by Mark Bell Mischief Theatre at the Lyceum Theatre; open run