It’s quirky and it’s original and entertaining. The music and visuals and acting are outstanding. And yes there’s a happy ending.
The hero is a boy and the heroine is a girl, both somewhat dysfunctional. Well, so were their families.
Placed about 40 years ago on an island off the New England coast, the story becomes mythic, with unknown youth actors interacting with unknown and known adult actors (such as Bruce Willis, Bill Murray, and Tilda Swinton).
It is a compliment to the movie that the “known” adult actors never distract from the story. It is also a compliment to them.