In terms of Genre, i'm pretty sure that the Corruption/NTR theme is gonna stay the core of N_Taii's games, so are the pixel graphics if you ask me, but i can see N_Taii making a game that's separate from the Henteria series. I'd love to see a steampunk or even a modern style game but the problem with those is that compared to the medieval setting where it's mostly just nature with the exception of a few houses here and there, a game that's set in a steampunk era has a MUCH denser enviroment, therefore it takes more time to create maps for it, or so i would imagine, after all i've never made maps of any kind.
As for your furry comment...as long as there is corruption and NTR involved i'm pretty much in, but i don't know how i'd feel about spending money on a game that has Furries in it, or i guess i do...so i REALLY hope that N_Taii isn't wired that way.
I'm almost certain that when you said "other types of characters" you meant different species like furries, but i'd rather have N_Taii stick with humans and elves, but next time instead of using the ol' reliable teen MC with the Mom/Sister/Female best friend setup, i'd rather see him make something more...original, i guess. For example a middle aged MC with a wife and 1 or 2 daughters, i guess the Mom/Sister theme could stay as well, but since the mc is a middle aged man here, the mom would be more like a younger grandma and the sister would basically be the middle aged aunt to your daughter(s) with a family of her own.