Are we grimmer or dumber or colder than we were in 1991, when Frank Rich, in The New York Times, called Scott McPherson's "Marvin's Room" "one of the funniest plays of this year as well as one of the wisest and most moving"? He did so even while noting that this "healing" comedy, then opening Off Broadway, featured three major characters dying or disintegrating - and a bunch of others arguably worse off. I ask because the Roundabout Theater Company revival that opened on Thursday, giving the play its Broadway debut, barely seems to be any of the things Mr. Rich listed. Thoughtfully directed by Anne Kauffman; keenly performed by Lili Taylor, Janeane Garofalo and especially Celia Weston; a pleasure to watch throughout - it is all of these. But it is somehow, also, fatally mild.