Scary doesn't mean monsters and jumpscares every two seconds. A game or movie can be scary solely based on it's atmosphere. Of course it's usually better to include a monster of some sort because it's incredibly difficult to do without one, but it's still possible. If you don't want the game scary, then why are you in a liminal jam? The entire reason liminal spaces have resurfaced is because of liminal horror, which is also mostly based on atmosphere. Excited to see what you make, though. (if anything)