Yes, it is a true comedy, unlike most Williams, in that it not only has laughs, it also has a happy ending. And it generally has a lighter feel than most of his plays. But in general it's always good to remember (and for directors and actors to remember) that his plays are funny, and he meant them to be. I can't remember where I read or heard about how when he would go to performances of his plays, which he liked to do, people would often complain to the house staff, "Who is that annoying man laughing so loudly all the time?" And I remember Jack Lemmon, perhaps with James Lipton, saying that when he was a young actor in New York, he saw the original production of A Streetcar Named Desire again and again from standing room. Then he decided to see every show in town and clock the laughs in each. Streetcar had the most.