Jeremy Heilman’s review published on Letterboxd :
Not the most assured directorial effort by Zombie, but his bleakest. I’m almost thankful that it’s so haphazardly assembled, because its nihilistic national vision would otherwise be hard to shake right about now. This is outwardly a film about a crazed oligarchy running a Most Dangerous Game-style competition, which resonates, but there’s a darker theme here that haunts me post-Trump and it’s that unease that arises about looking a fellow American in the eye. The early gas station scene is the most unsettling sequence that Zombie has devised here, and later developments only further confirm those fears, building a sense of hopelessness that makes 31 feel horrific even if it’s not scary or well-made.