Having gone back for the Dungeon 12 title grind, and now being reasonably confident that I've found all the items (though I did check against the map posted on the devblog), final thoughts. The dungeon layout isn't that awful, it's just a bunch of cramped tunnels, made more confusing to navigate by blockages and staircase transitions. Unfortunately, it's less-detailed than some of the other dungeons; the terrain is unusually featureless, lacking the decoration and variations that give life to other layouts, which makes the cramped confines a little harder to navigate because every detail is a landmark that makes the passage more memorable. Surely there's spiderwebs, or eggsacks, or piles of dirt, or anything else at all that can be used to 'beautify' the dungeon, selling the theme better and breaking up the monotony with more detail? The cramped confines made for a lot of bad places to have enemies, and they often were in those bad places, becoming impossible to sneak by, which (combined with the combat stuff), made this a more frustrating experience than it needed to be.
Also, it took me a while to wrap my head around what was going on with the combat. Early in the dungeon, the girls really hate being impregnated with spider eggs (understandably!), and this gives them huge debuffs to both offensive stats, which compound as their bellies swell with eggs. Meanwhile, the strength of the enemies jumped up significantly from the previous two dungeons, both of which were less dangerous environments. This meant that previously-effective strategies of mass-debuffing enemy defences and hammering area attacks was generally ineffective, and I found myself struggling through brutal combats with dangerous enemies who easily had enough time to take out an unlucky girl over the course of a typical fight. I didn't have much luck attempting tanking strategies (in hindsight, they would've worked much better if I'd started off tanking, instead of waiting until everyone was pregnant!), and single-target debuffs often felt ineffective, given the larger enemy groups, made larger by newborn spawn. Even so, it felt that debuffs really were the way to go here; delay and disarm the less-concerning enemies while striking down single targets with powerful attacks from buffed attackers, instead of spreading ineffective AoEs. It also would've helped if I'd noticed the difference between eggers and webbers prior to defeating the boss, and in particular noticed how dangerous the ranged attacks from the webbers were, and how disinclined they were to do anything but use that ranged attack once any one girl was webbed. Meanwhile, while struggling with the combat and hesitant to add even more enemies to already-fraught battles, I missed the obvious intended solution. At max addiction, the girls get a ridiculously-huge damage buff from being pregnant, and become incredibly powerful. A more optimal way of playing this would've been to grind the fetish content first... a more defensive setup, prolonging fights as much as possible, resetting as needed, and Laying Eggs as soon as possible, even if it means losing fights.
Still... easily my least favourite Dungeon as it stands. I could see that changing if the dungeon was beautified a little, and the enemy move range expanded with more interesting and thematic possibilities. If the correct way to play this is supposed to be taking your time and dealing with it, it'd be nicer if the enemies wanted to take their time as well, fighting the girls with poison and debuffs and prepared defences and a sexier multi-step immobilize-and-impregnate routine instead of mostly just using scary direct attacks. As-is, repeated forced battles at a high initial threat level, chaining into compounding hits to my ability to respond to that, put me on the backfoot immediately and spoiled my enjoyment of a dungeon that wasn't actually as bad as it initially felt.