S. Craig Zahler's horror western has been described as John Ford's The Searchers meets Alexadra aja/Wes Craven's The Hills have Eyes. This is an accurate decision as the film combines the racial politics of The Searches with the extreme violence and clashes between the civilised and uncivilised both of whom have the capacity of the violence in The Hills have Eyes.
When genres are mashed together it can be difficult to create the essence of each particular genre, in the case of Bone Tomahawk the film has little issue of combing the two genres as the film will appeal to both Western and Horror fans. The film captures the dark morality and brutality of the American Frontier found in many Western films, and the film's cinematographer also captures the frontier's sparse and grand landscape which provides a daunting and never ending challenge for the posse looking to rescue the kidnapped victims.
From the horror side there is also much to find that will appear greatly to the horror fans. The film does a masterful job at building the tension and mystery surrounding the cannibalistic cave dwelling tribe. Also, as the posse approach the cave the eerie and scary animal noises emitted by the cave dwellers is an incrediblly unnerving one to hear in the dead of night. The film's extreme violence and sheer brutality of the cannibals adds to the horror due to its unflinching and sudden nature, often there is no warning for the brutal violence that occurs.
A simplistic plot synopsis of the film could easily give the impression that the film is a violent (which it is) romp that immediately throws itself into the action where the central character slaughters these cave dwellers (which it doesn't). Instead the film takes time to build character, focusing on their interactions and motivations as they seek to rescue the kidnapped victims. It's because of this time devoted to character building that the explosion of violence at the end becomes far more effective as we begin to care about some of the characters. The performances themselves, particularly Matthew Fox, Kurt Russell and Richard Jenkins (the film's best performer), are all terrific.
Eli Roth's The Green Inferno saw numerous difficulties up until the film's release which delayed the film's release until 2016 when the film was eventually released, almost three years after production began. The Green Inferno is a film highly influenced by the 80's Cannibal Holocaust as it's about a group of activists who find themselves at the mercy of a cannibalistic Amazon tribe.
I would happily sit with Eli Roth and discuss horror films until we reach our demise, but The Green Inferno is clear evidence that the guy is incredibly immature. This is evident from the jokes he cracks about wanking, diarrhea, stoned Amazon tribes with the munchies and the use of the word 'gay' to describe how bad something is (I'm quite sure my generation no longer uses that word, in fact that's the first time I've heard someone say gay in that context for a long, long time). These moments, which fail to generate any humour, are utterly unnecessary.
Outside of that, however, Eli Roth is producing exactly what his fans want with his traditional extreme gore style of filmmaking. Aside from some terrible GCI, the film is well made, at times very tense and unnerving and gory enough to delight even the hardened gorehounds. Overall, it's a competent film let down by its questionable maturity.