I thought about adding a spark effect like in resident evil (and another GB game I made last month) but I wanted to let the player wander around in quiet and discover things by himself. Since there are no NPC's and going through the front door let the player understand he can investigate the environment, I thought he would end up investigate things. I did add subtle hints in dialogues like you said, I'm glad you saw that! I have already made a polish iteration for the dialogues, but I'll update the game after the Jam.