Todd Sullivan’s review published on Letterboxd:
There's a lot wrong with the Dark Tower film, and while I could certainly take my time picking apart those flaws, there's really only one gigantic mistake that I think is worth mentioning, and it's this: They tried to do too much in too little time.
I know a lot of people were initially freaked out about the film's 90 minute runtime, but that alone wouldn't necessarily be a problem. I mean, look at the first book in the Stephen King series -- it's under 300 pages. That's something that should be easily adaptable into a 90 minute film.
Mind you they didn't really adapt the first novel. In fact, very little, if any, from that first novel appears here. Instead, bits and bobs are taken from throughout the series, and mashed together in a way that is not satisfying and often doesn't make much sense.
Yes, the world of The Dark Tower is massive -- it's 4000 pages over eight novels -- but you don't have to fit every element of that world into the first film. Hell, half of the things that are referenced or appear in this film didn't show up in the novels until they were more than half over (and while that's likely because Stephen King didn't entirely know where he was going with the story early on, that doesn't change that those stories are no worse off for that lack of information).
All you had to do was introduce Roland, introduce the world, and introduce the central conflict -- his desire to reach The Dark Tower. Throw in a little Jake and some Man In Black and you've got yourself a movie that would be far more satisfying. In fact, you could even have The Man In Black as Roland's primary goal -- as was the case in this film -- and have the tower be a secondary goal, so you can have a satisfying resolution to the first film while also teasing a larger world and larger story.
Unfortunately, what we got was this, and holy God, this was a mess.