Tsuki Kagura was kind of bonkers, since you had western monsters (fairies, succubi, ogres, zombies, mermen, etc.) trying to rape the girls, and you also had Japanese youkai that you could recruit and summon into battle. And the Japanese youkai would need to seal the deal by fucking the red-headed demon queen that was the MC's boss in that game. (Meaning that when you won maps, you still got an h-scene between the ma-ou and the new recruit).
The dragon was actually a game-over, since it would fly off with whichever girl it had caught, never to be seen again (and you'd get a final birthing/egg laying scene depending on the girl after her rape).
Ama Kagura was an odd duck, since it was a bullet hell shooter with no scenes at all with the rank-and-file monsters that you mowed down, but every boss fight had a game over rape scene (your girl is the rescue team, and no one's coming for her if she loses), and 4 of the 5 bosses were fully voiced on top of that. You still got h-scenes when you won stages, since you'd get a "meanwhile" scene showing what was happening to the girl you were trying to rescue.
I'd love to see Nanaka, the albino girl from Ama Kagura, in another game, but I think her voice actress went main stream and doesn't do adult games anymore. Kind of a shame, her voice was really hot.
Yeah, her voice actress is Shizuka Itou (Akeno from Highschool DxD and Luvia from Fate, among many, many other roles). Highschool DxD is the closest she's done to hentai content in years.
Edit: So yeah, I guess if you want to hear Akeno getting jackhammered by a tengu into incoherency or desperately beg a horrible bug monster to not impregnate her, play Ama Kagura. Heh.