This review is only based on my first impressions after reading the 2 first volumes ! 3 and 4 are out since then, and each one is a real improvement. My impressions of this serie went from something interesting to one of my favorite novel, so don't think too much on some of what I say in this review. Sometimes reading a book purely based on it's cover really do end up nicely. I would not go as far as calling this an hidden gem, but it definitely is really underrated, or well, kinda not even rated at all currently. The story base is pretty simple; The author is a tabletop rpg fan, and wanted to share his sessions experiences, story ideas, tastes, fetishes even, through an absolutly not self insert protagonist getting isekaied. This also imply that the "system" the story go with is similar to the tabletop rpgs he's used to, instead of the usual Dragon Quest cospaly, with levels, stats, and skills. It is a much more personalized one, allowing the protagonist to evolve in more creative ways. Not a world changing thing, but definitely a nice touch.
It is pretty obvious that said author didn't have many writing experience just by seeing the style and the weird directions things sometime go. It's not to the point we can get lost, but it does feel bad to have many scene get suddenly cut, for exemple. Yet, this weird style successfuly convey what it need, and is part of what make this story have an unique and surreal atmosphere. The way some scenes are described really add a lot as well, and even something as simple as a second moon or the way magic work will feel impactful in many ways.

Art : 9/10
Here's the other important point participating in the above named atmosphere. The illustrations are amazing, and really give some flavor to many scenes. My favorite moment of the story so far merely is the introduction of one of the character, near the end of tome 1. But not only the way she show up is hella cool, but her illustration simply is perfect. It's an obscure reference right there, but the visual and overall atmosphere kinda gave me the same feeling as some Liar-soft visual novels.

Story : 7
The story is simple yet perfectly enough to do the job, and show a few very good ideas. Same could be said about the world building, it seems basic but has every needed details to make it a proper world, and some distinctives additions that make it unique.

Character : 7
Characters are fleshed out as well. The protagonist thinks well, the harem do it's best to not be too superficial (it still kinda is, not gonna lie), and I really liked that even antagonists get their proper story, chapters from their point of view, goal, etc. It might sound basic, but really, not that many stories bother with that as much.

Enjoyement & Overall : 7

It's a flawed novel in many way, again to me the worst was to have many scenes get interesting then suddenly cut and ignored to get to the next chapter. But it still was a very enjoyable read. I definitely recommand it.

ps : The author might have a bit of a monster girl fetish, don't worry even if you don't understand it's fine. Probably.
ps2 : 7 might seems weak to some MAL users but is very good for my standards