Very big, you've certainly got a lot done.
I really liked exploring the levels, especially when I got to the library area.
Excellent level design, I'm excited to see how you are going to implement more game play mechanics
The only things I noticed were minor glitches with walls and (the tiniest amount) of awkward placement of some unmovable objects, although I feel bad pointing these out because I'm certain you are already planning on smoothing things out and chances are you already noticed them.
I am very surprised at how well done this is though, especially for someone who has started hpl editor and scripting in less than a week!
Looking forward to seeing your progress on this promising project