I really enjoyed how YASSY played with the concept of the "ero dungeon" in this one. That the ero-dungeon is just a dream machination of Doremy for fap fuel is a suprisingly satisfying explanation compared to an ero-dungeon arising in Gensokyo or just plopping the character into one with little explanation. I feel the book is too dense art-wise, like @壹只影贝 mentions. It would've been better to draw it out a few more pages.