As a novice developer, it is difficult for me to understand what will be understandable to a person and what will not. But despite this, I try my best to make the mechanics of the game as clear as possible, so that the context is simple enough. So I intentionally didn't add any extraneous sounds to the background to emphasize the silence, and I also intentionally made the sound of the door opening loud enough to give rise to the idea that anything that makes a sound is dangerous. Perhaps now my hints are largely incomprehensible to people.
In the description, I described in detail (in my opinion) the basic rules of the game, I hope this will help people understand how it works. Of course, I understand that everything in the game has to be mastered in one game, but due to my limited experience, I'm not capable of it yet.