‘Back to Black’ isn’t great. The initial portion of the film, roughly the first thirty to forty-five minutes, is rough going; it has a very uneven start. Getting acquainted with the characters felt strange, and the unplanned instances of the main character singing... were almost embarrassing. I will say that after this point, the movie does get better—it’s funny, really—once the song that gives the film its name begins to play, I started enjoying it more. Regarding the cast, Marisa Abela is adequate as an actress; I'm not convinced she looks like Amy Winehouse, but I don't know much about the musician beyond her later years, so I could very well be mistaken. Her accent also seems unnatural, although that might be similar to what I mentioned regarding her appearance. It felt like I was watching Abela pretending to be Winehouse rather than seeing Winehouse portrayed by Abela. What I mean is, in the best biopics, it feels like you’re observing the person who lived, almost like a documentary, but here it was more apparent that I was watching someone play a part, if that makes sense. The same applies to Jack O'Connell; I don't know anything about Blake Fielder-Civil, yet he still seemed to be deliberately copying someone. There are some good things, though. Lesley Manville delivers a strong performance, and her scenes with Abela are where the film shines. Eddie Marsan is also dependable. It manages to make you sympathize with the central figure, even if that isn't particularly challenging. Winehouse’s well-known songs are included effectively; I always liked ‘Valerie,’ but that title track is truly remarkable. It’s undeniably tragic how Amy Winehouse’s life unfolded; I was aware she died young, but seeing in the final section that she passed away at just 27 really has an impact... such a loss. As for the film itself, it's not terrible, though.

Source on TMDB