Blue Core

In a darker take on the Dungeon LitRPG genre, the author posits a setting where Dungeons are a lot more organic than usual; rather like giant hollow sedentary magical tentacle monsters. Another novel addition is the Depletion mechanic, that lets Dungeons steal lifeforce from nearby creatures, permanently weakening them in the process. Oh, and in keeping with the 'organic' theme, Dungeon monsters aren't created from thin air, but must be gestated in a host.
By implication, the typical Dungeon in the setting is a creeping engine of destruction, sluggishly ravaging the countryside around it for building material, lifeforce and unwilling hosts - while under the control of a ruthless Mage King that feeds it slaves in exchange for magical and military power. 

So far, so evil.

If the background is dark, the foreground is a bit lighter, though. 

This is the thrilling tale of the MC - presumably a reincarnee from Earth - growing to be the nicest Dungeon around, taking in refugees from the rest of the crapsack setting, and, presumably, starting to make some badly-needed changes to the world. 
This is also the thrilling tale of beautiful women finding themselves in situations where it makes sense to volunteer for a torrid time with twenty-or-so tentacles, something that just so happens to align nicely with their secret desires. (Or so I extrapolate.)

The story is told well, and is interesting and engaging - with the occasional explicit scene, clearly marked in the chapter title. As for the style, my only complaint is that occasionally setting and character descriptions are a bit too bare-bones. 

The grammar is excellent, averaging less than one typo per chapter, with only the kind of mild grammar issues that makes me go 'eh, not really worth commenting on'.

The characterization lags behind a bit, simply because not many characters have been introduced yet, and there hasn't been much time to develop them. I'm willing to take it on faith, though, that future chapters will catch up on that front. 

It's early days yet, and it remains to be seen whether the story will be an epic tale of a world in change, or just a framing device to marry the Dungeon construction to the smut scenes with a minimum of fuss - but 23 chapters in, I'm optimistic.

One of those stories where you March along devouring chapter after chapter. Then the most terrible of things happens.. The next chapter button is greyed out.

Well written story, the world is interesting, and incredibly, the tentacle porn didn't turn me off.

 Let me start by saying that this story had everything to end up in the garbage bin for me. Rapey tentacle dungeon could've ended up terribly, but it didn't. Thats what surprised me.It starts off pretty generic as your dungeon stories go, but it was well written and concise thus I kept reading. The first "explicit" chapter was the breaking point for either dropping or continuing it.

I wasn't disapointed, not being a huge fan of tentacles I was pleasently surprised by how "good" the explicit chapters were. Specially because mr.author took the "willing shared pleasure" instead of the "rapey vore" route (which was what made me drop Everybody loves large chests).

So far the story was to my liking, the background story is interesting, the Sex scenes were well written and not "sanity decreasing", and although the characters haven't been fleshed out yet (well except for fox girl, we know plenty about her "flesh"), the story is good and I'm interested to see whete the author will take it.

Good start so far for this dungeon story which does things in a different way.

I really like how the author has done the world of this story, its a unique take on the otherwise stale dungeon genre.

The world is a dark world with mage-kings ruling all through the power of their red dungeon cores, commiting dark acts in the pursuit of power . There are the great dungeons, with their incredible size, unclaimed by other powers, being a danger to all who delve in their depths. The denizen of this world suffer from the power of the dungeons and the mage-kings behind them, with them losing their strength due to the dungeons draining them and filling their depletion.

In this dark world the MC is reincarnated as a dungeon core, and through a series of events, he becomes a blue core, the implications of what he is are massive, and could bring a change to the world and all its denizens.

The author has gotten a good balance between plot, and explicit scenes, even if i personally wish there were more of such scenes in the story! The acts are quite well described with it being a different type of sexual scenes. This is not simply sex just because, it does matter to the overall story, with some of the important powers of the MC revolving around sex, i cant go too far into this, since that would be some spoilers, more interesting to find out while reading the story, and the scenes are worth it anyways!

I have to agree with another reviewer that the characters while being good so far, still have to be developed much more, but i guess that will be solved over time as the author writes more of the story.

Consistent grammar in this story, it wont be a problem at all for the majority of readers.

Im interested in just where this story can go, it has so much potentional because it does it own take on the dungeon genre. I can already recommend people to read it, not only for the dungeon setting, but also for the explicit scenes (with added tentacles, if you need any more reasons to read it)

Besides that it's a fairly interesting dungeon core story, too early to tell where it'll end up but there's plenty in place already to lead to something good with a few wholly unique world mechanics already introduced. 
-edit- with the most recent chapters it is clear that a lot of thought has been put into things, I stand by my 5* rating and can't wait to see where things go.

Almost non-existent typos, wonderful storytelling and narration, depictive scenes, interesting sex scenes and a unique take on dungeons in fantasy worlds.

Oh and did I mention the update speed? Sweet.

Very good story so far, not much is known about the world at large, yet. Definitely a story I am happy to recommend to atleast give a try.

It's a fine dungeon core story with some (skippable and labled) erotic chapters sprinkled in. Unfortunately it runs out of steam after the Tor Kot battle and further chapters have become increasingly difficult to get through. Blue Core seems to have fallen into the same trap a lot of these dungeon core stories do which is that when they are focused and smaller scale they can be quite compelling, but as they grow larger and introduce more characters they become increasingly unfocused and lose their momentum.

The bones of this story are good. The harem characters are more diverse and interesting than usual. The antagonists are far better than usually found in dungeon core stories and the hints that the mage kings are actively fighting an existential threat make for what could be a very interesting dynamic later. If only this stuff wasn't burried underneath so much content that doesn't seem to be driving the story at all.

I think the story could be revitlized by liberal self editing. The main problem is just that there is too much inconsequential content in each chapter. Trim the fat, tighten up the plotting, and work to start building that momentum again.

I would like to preface this by saying InadisablyCompelled is far more skilled than most Royal Road authors. This review is primarily going to be for the author, given the amount of positive feedback when the story first came out, which isn't entirely representative of its state today. These reviews, while certainly correct in a lot of ways, haven't acknowledged a single glaring issue I've had an issue with for quite a few chapters.

Let's start with the good parts of the story first.

Character

Arguably the strongest part of this book. The characters are all believable and engaging. Despite there being multiple perspectives, the story doesn't fall into the trap of having a confusing and unnecessary amount of characters. The only issue is that the main character can be somewhat bland at times, but that's shored up by the presence of more interesting perspectives. Most other reviews have said the same things I have, so I'll be moving on.

Grammar

Almost impeccable.

Story

Although the story has laid a good foundation, its direction is inconclusive. Much of it is episodic. Each arc has a general goal, and then we move onto something entirely different. There are a few plot threads that have been put out there, but the pacing of the story means we won't get to them for another year. As far as I can see, the plot has no end goal, and that concerns me.

Style

By the gods, I can't force myself to enjoy it anymore. The amount of filler kills me. When the author is writing plot-relevant content, and social interactions, it grips you from the start. I feel engaged and interested in the world or its characters. Yet, the author doesn't seem to know how to write things that happen between the relevant parts. There was a period of multiple chapters that was just the main character info-dumping pseudo-science concepts on the reader as he talked about the development of his dungeon. When someone can skip an entire chapter, and still have a complete understanding of what's going on, there's an issue. The general formula of the book is 10 chapters of interesting and engaging plot developments, and then we'll have to sit through another 10 chapters of all the main characters preparing for the next plot development. These chapters are often filled up with unnecessarily detailed descriptions and monologues about things that don't matter. At times it's felt like I'm going through a middle-school grade science lecture, except the knowledge is about how to use a magical anvil to create beta metals using mana leylines in the metaphysical currents of reality, without altering the basics of Akasha runesmithing. The author could use that entire made-up description in place of sections detailing the long and complicated crafting process, and in my opinion, it wouldn't change the story at all. The combat is much the same. Often unnecessarily descriptive and boring to read. Although the shorter, more concise fights are interesting, there's not a lot of incentive to read through the longer ones.

Conclusion

Once again, I love this book and its characters. It's an amazing story in almost all aspects, but the filler between plot developments is often unnecessarily long and bogs down the pacing of the story to the point where I can barely read it.

Oh, the sex scenes are also great.

Compelling, well thought out, detailed, yet with an excellent pace to keep your interest. This story is one of my favourite dungeon core fictions now (and I've read almost all of them). If you like dungeon cores and magic, then you will love this story. Note about the rare "Explicit" parts: though brief, they're tasteful and high quality, fully consensual, with no negative outcomes for either party, with actual impact on the plot.

Overall: 5/5 for addictive storytelling. I can't wait for the next week's chapters!

Style: Great pacing, insightful POV changes (not too rapid, not too stagnant either).

Story: Interesting backstory, despite MC not having much of a past. There is a full world in the fiction that feels alive and interacts behind the scenes.

Grammar: Nearly perfect, only a minor typo once or twice a chapter, with appropriate punctuation usage in nearly all cases.

Character: Each character seems to have a proper feel of a backstory, with internal wants and needs, unique personal issues, and individual agendas. I do not get the feeling that any of them are 2-bit villans other than the BBEG the mage-kings (and their direct subordinates).

Another victim of the Telling Syndrome.

Way too much telling, not enough showing. There's also a TON of useless thoughts being thrown around, biggest offender being Blue wondering to itself what to do with this and that, only for it to not have any impact on the story whatsoever.

Still, I've learned how to skip over the filler paragraphs (they can easily take up more than half the chapters) and what I'm left with is an okay dungeon story. 

And for RR standards, 'okay' is pretty damn good for this site.