I was worried it would be perceived this way, but decided to carry the idea anyway. The thing is that all characters are isolated inside the house, so the killer has to decide when and how to strike. Pretty much like all characters from "And then there were none", but seen from the perspective of the killer.
Same with the limitation: It's not that there aren't any things while playing the game, but it's the final condition for winning: There are no living things left alive in the house.
Thanks for playing though :-)