I happen to believe that Peter Bogdanovich is an astonishingly undervalued director. Those who feel it worthy to mention him at all usually hand out praise to "The Last Picture Show", but his output since that milestone - such as this and "The Thing Called Love", for example - undeservedly gets lost in the shuffle.
In each of his films I have seen, Bogdanovich displays an extraordinary level of intimacy and comfort with his characters. We get drawn into their struggles because they are shown to us as fully fleshed-out human beings, not because manipulative elements like the score instruct us how to feel, at what time. He is able to draw our attention neatly to the vulnerability that exists inside everyone, regardless of external appearances. Such an ability is crucial to "Mask" and its overwhelming success in making us care about what happens.
Particularly good is how deftly the fierce bond between mother and son is illustrated. As I was once a disadvantaged child myself, I know that what makes a good parent isn't always signalled by a cheerful disposition, but instead security comes from the knowledge that you have always been loved. Whatever may be on her list of faults, you are never allowed to dismiss the love she has for her kid.
So, if you're looking for a journey over sometimes bumpy terrain that never forgets about the joyous qualities in life, then "Mask" would be it. It's amazingly affecting and is further demonstration of Bogdanovich's wonderful artistic gifts.