Interesting, what exactly do you mean by pixel art? Because it may mean just using different art technique to achieve same graphical fidelity like you doing now or somewhat a regression in that regard closer to how CB looked. But mostly I'm curios to see,
And second question souls-like in how combat works or in other aspects? Mostly because many hentai games that used that model had only on defeat adult scenes (also many guro) which I'm personally not fan of. Plus none have option to make succubi/incubi build (you need your enemies virility to survive :P)...
Good luck