The film shares quite a bit of commonality to David Fincher's Se7en. They both feature a serial killer whose victims are chosen based on a religous theme. The killer reveals themselves to the police before the end of the film (and before the police are able to catch them) and the killer makes the chase personal for the detective. Se7en is a masterpiece by comparison though.
Whilst on the topic of commonality, I also noted several similarities in theme to the excellent Japanese horror film Suicide Club, only that too does a better job of explaining itself.
According to the IMDB there is a 110 minute cut of the film and I would really like to see that, but for this viewing I sat down and watched the 90 minute version (currently the only one available). The pacing is extremely quick and gives you no time to absorb or reflect on what is happening in the film, I feel this may be in part due to the fact that if you did start reflecting you would see quite a number of plot holes and inconsistencies. I can't say I was surprised by the ending, but it is still a little disappointingly rushed and leaves you with more questions than answers. Whether or not an extra 20 minutes would help though is open to conjecture.
The film has a very strong cast, most of whom are incredibly under-utilized. Appearances are made by Ziyi Zhang, Patrick Fugit, Peter Stormare (who has roughly 2 lines of dialog!?) and Lou Taylor Pucci.
For the most part The Horseman is a decent enough thriller and to the untrained eye may even give a few twists and turns along the way, but if you haven't seen Se7en, I would strongly recommend doing so and saving this for a rainy day when you just want something to watch....