An impressive scripting debut for actors Matt Damon ("John Grisham's The Rainmaker") and Ben Affleck ("Chasing Amy"), "Good Will Hunting"--perhaps in part because it feels so little like a film by Gus Van Sant ("To Die For," "Drugstore Cowboy"), who directs--drew the second-strongest audience response at ShowEast. And deservedly so: This story of a college-age math savant, Will Hunting (Damon), who appears to have no chance of partaking of the Ivy life due to the hard-scrabble existence he's been living since orphaned on Boston's South Side, usually plays at a level of fine human emotion and makes little allowance for sympathy shortcuts in its dramatics. Even the appearance of Robin Williams as a concerned psychologist doesn't deter Damon and Affleck from their course; though elsewhere--as in "Dead Poets Society"--given to misty-eyed emotionalism, Williams delivers an honest portrayal that adds greatly to the film's character interplay. Yet audiences drawn by the Van Sant credit are likely to be surprised at least, and disappointed at most; "Good Will Hunting" never veers from a mainstream course, again recalling "Dead Poets Society," in which Peter Weir--noted for the singularly voiced likes of "The Last Wave"--made a resolutely ordinary studio movie. In boxoffice terms, of course, "Good Will Hunting's" appeal to the mainstream is all to the good. Helping matters along are Affleck as Will's hard-hat friend and Minnie Driver ("Grosse Pointe Blank") as Will's Harvard-student girlfriend, both providing effective turns as characters who in their separate ways help push Will toward a resolution of his personal problems and the achievement of his potential. Starring Matt Damon, Robin Williams, Ben Affleck and Minnie Driver. Directed by Gus Van Sant. Written by Matt Damon and Ben Affleck. Produced by Lawrence Bender. A Miramax release. Drama. Rated R for strong language, including some sex-related dialogue. Running time: 125 min.