There are some significantly positive elements of the film. I am not sure there are many better actresses than Joan Allen at portraying the challenged, but loyal wife. She did much of the same in the film, "Nixon." The other strength of the film is that it possesses an all star cast, actors that have to be considered some of the strongest in their craft. Daniel Day- Lewis, Paul Scofield, and Peter Vaughan have put forth great performances throughout their career. The strongest challenge the film had was that it was never going to match the play. Even though Miller wrote the script, his play has become a landmark of American Literature and stands on its own for both its content and technique. It is difficult to see how this could be translated into film, and in the end, many felt that the film possessed good ideas but never fully was able to materialize them into what was present in the play. Roger Ebert's review argued that these ideas never quite developed in the course of the film as they should have and this level of disjoint helped to detract from the full enjoyment of the film as one would have enjoyed the play.
The movie The Crucible is a pretty good one, but nothing is as good as the book or play when put on the big screen, and this is not an expception to the rule.
One of the strongest points of the movie (which is what I think you are asking about) is the character development of John Proctor. You can feel his struggle to please his wife although their relationship isn't the best because he feels guilt for cheating on her.
A weaker point of the movie and the play is what comes of Abigail. I don't like that she gets away. I want her called to account for what she's said when Hale figures things out. It's just understood that she is out of the picture as she went away.