Add artifacts. For example, a broken radio and part of it, or a broken phone, or a bottle with a message. So the game will be more atmosphere. Say: find all the pieces of a broken radio. Trying to find the radio signal. There were disturbances. You hear a voice. But suddenly the battery dying. And that's it. So as with telephone and letter in a bottle. It will be very atmospheric.
Also add alternation of day and night.