Well. The first book in "The Dark Tower" series. Are there some issues in this book? Yes. The pacing gets a bit draggy towards the end. But the world building is really good as well as the plot in this first book. It's enough to make you want to run out and read "The Drawing of the Three" or maybe that's just me.
"The Gunslinger" starts with someone just referred to as the Gunslinger following the man in Black. You don't know what's going on between them, but you realize that the Gunslinger has no intention of stopping until he catches up with the man in Black and they will finally have a confrontation that has been a long time coming.
I think King is smart to show that you may not like the Gunslinger. He shows you early that catching the man in Black is all he is focused on. Stopping in a town that appears to be on it's last legs, he sleeps with a woman he doesn't care about one way or the other. While there he runs into someone from his past and you realize it's probably best when the Gunslinger is indifferent, because when he's angry, that's a sight to see. But we also get to see his brutality while he is there, and you start to wonder should you even be rooting for this man.
Besides the Gunslinger (Roland) we also have Roland coming across a Boy (Jake) that has somehow come from another world and dropped into Roland's. Roland and Jake fit together for some reason and Roland has affection for the boy, but still has no intention of not doing or using anyone to get to his goal. You start to worry for Jake and there's a pivotal scene between the two that may have you hate Roland. Or maybe that was just me.
The writing I thought was good. It may be hard to understand some dialogue since King has the character's using High Speech at times that reads as broken English (see thankee sai). The flow as I said was good until we got to the end. Then we got a big dump of information on Roland that didn't really fit the book. It helps set the stage for "The Drawing of the Three" though so I can see why King did it that way.
The setting of Roland's world is similar to our world in parts, but different enough. He is a descendent of Arthur Eld (similar to our world's King Arthur). The gunslingers are similar to knights, and our Roland is off on a quest. Instead of the Holy Grail though all he wants is The Tower. I loved that the world building wasn't so explicit .You are given hints and guesses about what has occurred, but thankfully no information dumps by random people (one of my pet peeves).
The ending leaves enough for you to want to continue the series. I plan on rereading this series throughout the year in memory of my dad. He was a huge King fan, and because of him I am too. The Gunslinger was the first book of King's I read and loved. Thankee sai.