With its peerless cast, handsome production, and generous comic spirit, The Impostors, writer/director/co-star Stanley Tucci's follow-up to his (and Campbell Scott's) delightful Big Night, would seem to have everything going for it. But this broad period farce, while meant to evoke Laurel & Hardy and the Marx Brothers, instead plays like bad community theater, well-intentioned and exuberant but pitched to the back row. As a pair of unemployable stage actors in the '30s, Tucci and Oliver Platt fare well in the promising early scenes, which include a graceful staged brawl over the opening credits and a scam in which they try to bilk a genial pastry chef out of his creme puffs. Once they re-surface as stowaways on an ocean liner, however, the cascading comedy in The Impostors not only fails to snowball; it nearly drops off altogether. In the gifted, Grand Hotel-style ensemble, the less manic performers fare best, including Campbell Scott as a lovelorn but deranged German head steward, Hope Davis as a frog-voiced, depressive debutante, and the ever-reliable Steve Buscemi as a suicidal entertainer with the ill-fitting stage name Happy Franks. All the actors look like they're having the time of their lives; Tucci, to his credit, unabashedly loves his fellow performers. But their unchecked zeal only aggravates material that would sound strained enough in a cold reading.