I would suggest with the Feminization theme - growing Breasts just like the Slime implies on you or after the Bunny Queen knocks you up. Perhaps a certain enemy - or after being bred too many times you start to grow them as your feminization continues. It could unlock new sex scenes like being made to give boob job blowjobs to the Futas or just being groped and ravaged.
Perhaps even a lactation fetish linked to a impregnation fetish - which again is the game over from the Bunny Queen. But more of that would be amazing
A larger variety of things the enemies say like 'you let me catch you' and stuff like that is also crazy hot but more impregnation lines.
So more of everything you're doing - but also growing breasts as the Futa cum changes your physiology.