Enemies are not good. They don't match the horror the game is trying to convey. Also, being able to attack enemies makes them boring. So the enemies suck. Except The Gray Rock Worm of course :)
I think the game derives its power from the abstract mechanics between the sense of curiosity and the fear of the unknown. The tension remains there throughout the game, even though there are no enemies.
It is extremely successful for a game made to establish a setting.