Summarize the following movie reviews:

1. The film proceeds in what feels like real time, but with no obvious beginning or end. It's a latticework of moments happy and sad.
2. A movie that rumbles around inside you and appeals to those who believe in love as well as those who recognize its potential to fade.
3. Blue Valentine is so nervy, so "real," that it poses a dire threat. Dean and Cindy are such decent folks. How do we know what happens to them couldn't happen to us?
4. Blue Valentine is interestingly styled and shot. It features outstanding performances from Ryan Gosling and Michelle Williams and an inventive screenplay and structure.
5. Cianfrance dives deeply into the happiness and heartache a damaged relationship can give you and has created a story that understands how real life romance actually works.
6. BLUE VALENTINE shows us the present will never be as fun as the past.
7. The ghost of John Cassavetes looms large over Blue Valentine. This movie destroyed me.
8. What we end up with here is 2/3 of a story that consequently feels incomplete. It obviously wanted to be something like "(500) Days of Summer" in terms of structure, but the writers just didn't know how to get up to that level.
9. [Director] Cianfrance is not interested in the Hollywood fairytale, he want to show that love can scar.
10. Unlike Bergman's searing Scenes from a Marriage, which sustains itself for every one of its 299 devastating minutes, Blue Valentine begins to falter somewhere during its 114.

Summary:
This emotionally gripping examination of a marriage on the rocks isn't always easy to watch, but Michelle Williams and Ryan Gosling give performances of unusual depth and power.