The title sums it up. Explorers of the Abyss is a great dungeon crawler if that's what you're looking for. The game has great H-scenes, in my opinion. Where the game goes wrong, however, is in its gameplay. Battles in this game take the form of random encounters in the abyss, and these random encounters happen so often (like, every step or so) that, unless you know exactly where you're going, slows down progression in the dungeon. So far, I haven't found a way to travel to individual floors (if that's even a thing here), so when you leave the abyss and want to go back, you have to go through every single floor and random encounter.
Second: This one is a personal one, you can't explore the town. You navigate different parts of the city through text.
Were it not for those two points, I would rate this game higher. But because the random encounters happen so frequently and just gets in the way, I have to detract two stars.
Honestly, if you're just playing for the H-scenes, play on "Cheat". The random encounters are still annoying, but the battles pretty much end instantly.

Good H-scenes, game itself is a pain, way too much backtracking, poor level design