I can see you put nice consideration into the graphics, although due to the sheer amount of darkness it's hard to see.
It's impossible for me to progress even through the first stage, as the key opens no doors ( this might be my fault, but I checked everywhere and found nothing ).
The controls are pretty nice ( allowing for both ASWD & Arrow Keys )
You did follow the theme, but since I cannot progress through the game at all it does ruin a lot of my experience with it.