It's pretty much a horror game based on slow-burn growing of suspicions and uncanny valley of "not humans", and in the demo even though there's no mention or tips on it there was someone who's a human but you shouldn't keep. This game gets my brain running trying to root out the "visitors".
Game is about deciding if someone should be let in after asking them a few questions at the door, and then when you let it in you still have to check night by night by asking them more questions and checking their body for telling signs. So why let anybody in at all? Well, not much of a spoiler but there will be a very overpowered monster who seems like the mastermind or boss, knocking your door and it can tell if you got people inside or not. If you're alone then... Game over.