It's most certainly a shift in terms of genre for this author, he mostly focuses on more slice of life and comedic stories. This appears to be the author's second attempt at a more serious storyline. the art of this story is also far more communicative in terms of narrative, where all of earlier works were more focused on simply showing off the protagonist's assets. The author appears to be at least somewhat restraining himself as while fan-service does remain a primary feature of this series, the background elements and narrative are becoming more of a driving factor to the progression of the story. Perhaps this can be best put as the author possibly branching away from simply going from one excuse to ogle his heroines to the next towards a story with a developing world where the bodies populating it are home to actual people with personalities that could be found in our own.
While this is certainly my favorite series the author has made so far, I still find myself putting Coco and Kuro ahead of this story as the author of that series puts the narrative first were as Crawling Dreams frequently alternates between fan-service and narrative as the driving force behind the story. Although I said that the author is straying away from writing purely fan-service stories, the series is still rife with chapters where the author is still relying upon the "sexiness" of his main protagonist. Even though the series would greatly benefit from abandoning these types of chapters, I find that the overall tone of the series would shift from a light reference reliant romp with a horrific underbelly slowly but surely coming to the surface, to a bleak humorless world without any real sign of levity to relieve the audience from the terrors the author has to offer. If the author truly wishes to create a more narrative based story I believe creating a new series would be the best option for him to retain the viewership built up from his other works, while shifting into a more story oriented manga. Will the author do this? Unfortunately it is far from likely, as it appears the author built his patreon upon selling access to "lewd artwork" and therefore has likely made fan-service into an integral part of his business plan. while there is most certainly nothing wrong with this, if the author were to suddenly truly abandon this, I would gladly pick up any new series he has to offer.