Up until now indie fave Greta Gerwig was known almost exclusively for her acting in films like 20th Century Women, Frances Ha, Lola Versus, Mistress America, Damsels in Distress, and Greenberg. Those titles may mean nothing to you. But to a certain audience, they mean everything. And that audience will eat up this film that Gerwig wrote and directed, and stars Saoirse Ronan (Brooklyn). It's a sweet, likeable coming of age story. Nothing we haven't seen before, but it's honest and enjoyable. I'm not quite as in love with it as other critics, but I'm definitely in serious like with it.
Who is this movie for? If you think you want to see it, you'll probably enjoy it. The audience that knows Gerwig and Ronan is the audience that will best appreciate it.