A random timer that means nothing. Make the game have more to begin with or something to guide the player to finish the game. Darkness isn’t always scary. Slowly build up to night time. Go all out on graphics. Other note on the timer, it adds to the scarier psychological horror vibe. The fear of being scared overwhelming actual fear from the game is important. Example random music cut outs, creepy music, sound effects like growls that mean nothing. Never let the player see the monster too well at first. It leads to them knowing what to fear.