Super creepy! This is honestly the first submission I've played where reading "Death is only the beginning" was genuinely scary. A dark, twisted and superb take on the theme.
The first shadow to appear in the game, the one running past, really set the mood right from the start. The ones which loiter around are also a nice touch, perhaps a bit too prominent to be as creepy. Which is fine, though, since the ones that attack you are plenty scary to deal with when they sneak up on you.
I think some sort of sound effect, a subtle one, to indicate there's an enemy nearby would really take it to the next level. Not necessarily a noise from the shadows themselves, more along the lines of the radio static in Silent Hill; an audible trigger which warns the player of danger and, more than anything, increases their paranoia.