Pretty damn scary, in my opinion. To be fair though, I have very little tolerance for scary games. Most players call the game more creepy than scary. It doesn’t rely on horror game troupes like jump scares or ammo scarcity, in fact, there is no ammo to speak of. The threats are all present and avoidable. The creepiness comes from the look and feel of the environment, the monsters that inhabit it, and the tense platforming.