Like roboMarchello, I also think it's neat that it's actually a huge area. Wasn't able to find the end location, though.
The tension of the slowly dwindling light really does build.
When I first saw the monster, it was only a shadow on the edge of the light. I don't know if that was scripted, but it really got me tensed up!
The monsters themselves weren't too scary, also the fear kinda dissipated when I was able to juke two monsters, going in between them.
Also, your main editor is neat! Hope you don't mind if I look at the source code and try my hand at designing my own map editor for future projects!