(Unfortunately, I wasn't able to properly enter because of exams. I decided to give it a crack anyway. Zerod, don't feel pressured to rank or mark this - I just made this for fun.)
I took the liberty of interpreting horror as cosmic horror.
Cosmic horror is all about coming to terms with your insignificance in the grand scale of the universe. The idea that there are greater beings out there that see humans as we see ants. We are but a small speck of blue in the endless void.