Everything goes terribly wrong in this steaming pile of garbage. I could hardly believe this was by the same director of "The Emperor and the Assassin".
The CGI was awful. The palace looked like it was from an 80's movie like "Tron". The running scenes looked like a car driving scene from the 50's where you have a glaringly obvious fake background in the rear window.
The editing was horrible as well. Jump-cuts have a certain role in the visual language of movies, whether indicating frantic behavior (the elevator scene in "Revolver"), showing something happening over time (somebody waiting in a room), or even cutting to the beat of the music (the intro to "Scratch", the intro to "Boiler Room"). There are so many places in "The Promise" where jump cuts are thrown in for no rhyme or reason. People are talking, and then all of the sudden it cuts, and cuts, and cuts in the middle of their dialogue, like someone keeps accidentally hitting the fast-forward button. It's almost like the crew didn't get enough film coverage, decided to get sloppy in the editing room, and said, "Eh, they won't notice." Well, I sure noticed, and it was so disorienting I felt like vomiting. Even Michael "ADHD" Bay's movies have better editing than this.
On the opposite end of the spectrum, I have never seen so many fade-cuts in one movie in my life. Practically every scene faded to black after 30 seconds, like the movie was a compilation of TV commercials or something. This totally killed any kind of flow the movie hadn't already destroyed.
Finally, many other comments have indicated the frustratingly illogical script. People do stupid things for no reason at all. I'm not even talking about movie logic, where you can temporarily suspend your belief. "Why is the girl running up the stairs instead of out the front door to get away from the killer?" OK, so that's typical movie logic, which you can easily explain away with "Well, she is terrified so she doesn't immediately think of that particular escape route. Anyway, the killer is chasing her up the stairs, so it makes sense." In "The Promise", you have things like an army sending several hundred slaves into a canyon to get trampled to death by buffaloes. Why? Does having them get trampled somehow help the army? Does it give them some sort of tactical advantage? No. In fact, why would the enemy even send buffaloes through a canyon in the first place when the entire good guys army is safely positioned on the ridges of the mountain? The answer, of course, is that the director said "Hey, know what would be cool?! A scene with stampeding buffaloes trampling people to death! YEAH!!" Then there are scenes over and over again where someone says, "OK you can go now. WAIT! You cannot go. OK, you can go now. WAIT! You cannot go. OK, you can go now..." I can safely say that best part of "The Promise" is when the credits roll, because you know it is finally over.