For me, it's few things. And take this with a grain of salt since I could very well be playing the game weird. Autism and all that.
One thing I think is a fun, but completely optional idea is more things for memory or perception manipulation. Maybe I just haven't been using it well, but it feels a little shallow right now. But only a little!
I've yet to experience the traitors or secret maids in the game since once the visitors actually figure out something is wrong, it feels like they really brute force the situation. Which I tern, gets either you or them walloped right away, leaving no room for strategy or deception. So maybe giving the visitors a chance to strategize, by barricading a room off, and giving us a prison for downed people would be fun. I also just don't know how to make deals with visitors since I only seen the option once with a hero during the final section, and I know how to make a secret maid but I didn't see much use for them.
The second would be combat, it's kinda... what's the best word... Simple? I don't know, it just feels like there's no depth to it if that makes any kind of sense. I know this isn't supposed to be a fighting game, and that's ok. I just feel like combat and the prospect of it is little more than an annoyance than anything else.
Now if you have any recommendations for things to try, please tell me. It's very possible and likely I'm missing something and just not playing the game to it's fullest. Oh, and one more thing. More outfits and customization would be splendid! I know that's kinda a nitpicky thing, but I love playing dress up with my metaphorical dolls in these cases. That's all I have to say, I really enjoy your games so far, but I will say there's a lot of things especially in your other game that just go way over my head. Even when reading through the tutorials, I'm not the sharpest tool in the shed.