For audiences unaccustomed to playwright David Mamet's claustrophobic, language-dense style, American Buffalo may be a hard film to watch. Primarily a three-character play with one main set -- a junk shop where two men and a teenaged assistant plot a robbery -- the film is more a character piece than a real story. As such, it is a marvelous study in language and personality, rolling along on the performances of Dustin Hoffman and Dennis Franz and Mamet's uniquely cadenced, blisteringly profane dialogue. The actors are all terrific, and young Sean Nelson (Fresh) more than holds his own with the veterans, but this is likely to appeal to theater fans more than casual viewers.