Where to begin. I always never know.
Plot-wise, it’s respectable. Where a typical harem story would be sexy women, sex, and the male protagonist being stupidly overpowered, the story substitutes more plot in place of sex.
The male protagonist is not lawfully good like most harems, but neutral neutral. When he obtains the means, he does whatever he wants when it means improving his own life. He cares for the girls as much as they are a means to his own ends; they are beneficial to him, so he treats them with basic respect to encourage cooperation and basic order.
Some girls have more relevant roles then others and none of them love the protagonist right off the bat. In other words, none of the events depict of an unrealistic standard of a girl instantly becoming infatuated (some do develop feelings, some more quickly than others, but none immediately) and obviously show it.
Each girl’s personality and alignment (lawful-chaotic, good-evil) vary as much as their powers, assuming it’s within the protagonist’s patience. I may have missed this if it said more than once, but their physical attributes are only described heavily once, so as long as you can form the image of the character when it happens, the story won’t be a blur.
For everything said above, the story could’ve been a five for me. What brings it to a four is there isn’t a fulfilling climax. If the climatic arc has a high peak, the story has waves; as a problem arrives, it’s solved. Nothing foreshadows a crushing obstacle as the character and his situation builds up for the better. As the character admits to himself, he reacts more often than he acts.
What makes the story unique is the lack of (or the complete absence of) a morally-good society. Though the girls are heroes (or so their previous society would label them), there’s no big heroic action done by anyone. Whether someone is a hero or villain lies in the eyes of the beholder (or reader).
With everything above considered, I personally enjoyed the story. I plan to reread it soon and would recommended it above other harem stories. It’s not incredibly outstanding, but it does stand above others in its genre.