Hey there, hope you're doing well. So I searched for horror and you showed up... I've worked on a few short movies just for fun and also, both the book and game, have a thriller aspect. And yes, it's best to show and not to explain cause the viewer will feel rewarded for discovering. Also, if we build suspense around the threat, the viewer will have expectations. Like the Jurassic Park dinosaurs, which first you hear then you see people being afraid and think "Oh my God". Only then do they show up, and it's amazing...