In a rare instance of a Nicolas Cage movie not sending him out for some kind of idiotic vengeance, Joe is a Southern drama that sees Cage as an ex-con trying to redeem himself by protecting a teenage boy struggling to support his family. As you can see here, you can tell Nicolas Cage is serious about this because he has a beard now, and, to a lesser extent, because he's dressed like MacGyver.
Beyond shifting Cage from always-shouted action to quiet, only-sometimes-shouted drama, the film is a return to form for director David Gordon Green as well, taking him back to his roots in contemplative indie drama (George Washington, All the Real Girls) after a long stretch with madcap pot comedies like Your Highness and Pineapple Express. In other words, Huey Lewis is probably not going to write a theme song about Nicolas Cage's beard. Isn't that stupid?