Re: parasite in city
in terms of feedback:
The immersion factor could be improved, basically a few things that will help pull the player deeper into the game-play and erotic scenes
1. sound. In particular moans during animation, sloppy slapping sound, liquid pumping sound ...etc. I've heard the same generic moaning sound across many hentai games, so I assume there's a 無料音楽素材 site to fill in these sound for free.
2. A clear effect when the girl has been raped a few times, perhaps an ero bar that increases whenever she is raped? Maybe the girl will limp and walk slower, getting up and resisting rape will of course get harder the higher the bar. It could be anything thematic: take more damage, faint/orgasm when bar is full ...etc
3. Something for the game over scene. In order of my personal preference

:
a) a "lair scene", basically keep the sprite animation format and show an "after" scene. For example, in the game UnHolY SaNctuaRy when you lose to sprinting orc or the dominatrix boss. In this case, a zombie "lair scene" could just be a double penetration with looping ejaculation and cream-pie, a fly "lair scene" could be a breeding chamber that shows a looping birth and impregnation cycle. Time wise may be impossible to do a lair scene for every creature, picking and choosing based on inspiration might be good.
b) something animated would be wonderful.
c) If resource constrained, CG would do in a pinch. Though I'd personally just leave the game over blank unless I could do multiple progression CG with sound.
Development resource / time is of course limited, and it's impossible to do everything fans want. I wouldn't sweat it, and just go with what you think is best to spend time on.
And of course, thank you for communicating with us gaijin game community, much respect~ Best of luck.