I'm not sure what to say about "The Dark Tower." I haven't read any of the Stephen King books it's based on. I knew nothing about the Dark Tower stories going in, and I knew exactly the same amount when it was over.
Here's what I can tell you. Idris Elba is the good guy. Matthew McConaughey is the bad guy. Tom Taylor is a boy caught between them. There's a tower that controls the universe, with portals between places on Earth and other worlds. There are children screaming, special effects galore, dark mysterious people and locations, and a plot that is totally incomprehensible.
Don't waste your time with "The Dark Tower." I give it a 2 out of 10.