I’m not into those kinds of games, but I happen to personally know the dev of “The Symbiant” (we are on the same city-wide Discord server), which is a yaoi VN with a side of tentacles. It seems to have excellent reviews (96% all time with 500+ reviews, a lot for this kind of games), but that’s the only one I may recommend, albeit without having played to it myself.

From what I was told by said dev, most NSFW games are Visual Novels, where most of budget goes into the visuals, which are often externalized to specialized artists (or AI for some low quality cash grabs). And as the target audience isn’t exactly there for the gameplay, there is little incentives to shape out good gameplay or great stories. But some exceptions probably exists.