TL;DR
Dorohedoro is a mysterious, chaotic adventure with lovable characters and an incredibly rich world. This review will be relatively spoiler free. I will mark any potential spoilers with a spoiler tag.
The story is well developed and surprising

This section of the review may contain spoilers. I don't go into the depth of the plot, but I do discuss the story structure. I also assume that you've read the synopsis. In my opinion, it might be best to read the manga blind.
Spoiler, click to view
The first half of the story is spent exploring the world and introducing the characters. There are many different events such as "Night of the Living Dead" and "Blue Night" to drive the character interactions while detailing the world. It's quite the slow burn, but the payoff is well worth it. The second half of the story is where the narrative starts ramping up. Elements of the story that has remained a mystery thus far finally start to connect. The change of intensity might be quite a different experience from the first half of the story, but it feels like the latter half is the result of what the first half has been building up. There are many twists and turns. Although it may be dragged out and convoluted at times, the story does its best in explaining why things happen, and it does it well, overall.The world is intriguing and fleshed out

The vile and grimy world(s) are easily the best part of this manga. The magic system is unique, the motivations of humans and sorcerers are believable, and the dynamic between these different societies are chaotic.
Spoiler, click to view
The devils, especially, give no shits about the humans and sorcerers, allowing them to act in very unpredictable ways and push the plot forward.The characters are unique in their designs and charming in their personalities

The character designs, especially the main cast, are memorable. Although few characters get development, they are well written for you to have a strong grasp on their personalities, motivations, and purpose. It feels like almost every character fits in the massive puzzle; little to no one is left unaccounted for in the overarching story.
The art is beautifully grotesque

To be honest, the art took me some getting used to. It's dark, detailed, and quite disgusting, to be frank, and I love it. It complements the world perfectly and is quite curious to look at.