..would be a more accurate name for the series. Seriously besides from so happening to be a place of confinement for the adventurer that bestows the Omnipotent Perversion skill on mc, there is nothing special about the dungeon itself. Even the "only I can enter" part is just plain false.
Now, the OP skill basically allows its user to instantly and remotely change add, or delete any properties of any object or living being(including oneself) by using perversion points. To gain them one must experience particular kinds of pleasure from tasty food and acquiring reaches to, of course, doing lewd stuff with members of the opposite sex.
That could be a fun concept, except the execution throws it completely off balance. And I mean to the point where mc gains more p-points than he used to defeat the final boss just by hugging his friends afterwards.
With that kind of power all his "struggles" seem like a crude charade. And of course mc had to be made insufferably stupid to not solve all the challenges in an instant. I mean he constantly wastes points on weakening a single enemy instead of strengthening himself, and so after the opponent is defeated all the resources spent on him go to waste. Also mc never attempts to find out how exactly points are acquired, deduce the mechanics and boundaries of his skill. On top of poorly using his skill, in both earning and spending, he also lacks in terms of common sense, enough to nearly never use the Great Sage skill(basically shares absolute knowledge), or to promptly trigger final boss despite knowing that he is 4 times the level.
What's worse stupidity transitions to the plot, like when requiring funds to save the daughter of the duke they never request money from the guy, taking part in a harem competition instead; or the ridiculous lion's predicament; or the fact that the Lucky Lecher skill obtained in e4 is simply forgotten henceforth.
In summary, despite a curious concept everything about the show is as crude as it gets.