I should have read some reviews before going to see this one. Having seen it now, I'd say this movie is a great example of a tale that doesn't give us any reason to care about what "they" are doing. As far as I can tell it's all Overall Story.
Jake Chambers, the kid, is the audience's window into the story, but he has no personal issues to give him a proper MC throughline. At least, anything that might have been personal to him was rolled into the OS.
I saw neither an IC throughline nor an attempt at one. Roland Deschain (the Gunslinger) was probably supposed to fill this role. He wanted revenge against the Man in Black. This was addressed in the film, but didn't particularly feel addressed. I kept waiting for the scene that showed what happened only to realize later that there was a scene that was probably meant to show it, but it felt only tangentially related.
The Gunslinger and the kid do some stuff together, so there may have been an attempt to hint at an RS. The RS isn't my strong suit so I might be missing something, but as little as there was to the MC and IC, I really don't think there was an RS either.
Roland and the Man in Black are the protagonist and antagonist, although i'm not sure if the goal was to destroy the tower (meaning the Man in Black is the protagonist) or if the goal was to save the tower (meaning the Gunslinger is the protagonist). However, I'd guess that it was the former since Jake and Roland speak about how Roland is more interested in revenge than saving the tower. But if that's right, that means it was a (spoiler alert ... ) story outcome of Failure. But that seems strange, because is seems like if the audience cared what happened (and I certainly didn't) the film would have wanted the Outcome to feel like a Success.
I could spot various situations, activities, fixed attitudes, and manipulations throughout, but most of them seemed to me like storytelling rather than sources of conflict.
There was plenty wrong (in my opinion) with the writing and acting (Elba was good, the best thing the movie had to offer i thought), but if the film had given Jake a personal issue to resolve, and if the Gunslinger had been given a chance to have any type of impact on him, it would have been a much better story. Even better would be if they had made the Gunslinger the MC and the MIB the IC. Either of those changes would have made the movie watchable, even if still not great.
All that said, I'll just say that it seems pretty clear that, despite what happened in the world of the movie, in our world The Dark Tower has already fallen.