There are three reviewers mentioned here at enotes: Allan Wallach, Clive Barnes, and Edwin Wilson. There are also some essays you might peruse on the topic. Follow the links below to find out what they say about the play. If you search "criticism of 'Fences'" in your search engine, I'm sure you will find more reviewers and critics of the play.
In a review of a 2008 production of "Fences," Jay Furst largely praises the play for its linguistic power and character portraits, but refers to its plot as weak, which it is.
A number of critical voices are summarized in the enotes study guide on the play, especially here:
Dr. Sandra Shannon