Really the best custom story I played so far.
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Your scripting was nice, the level design was new and fresh.
Only thing I did not like is that important items (like the lever handle) were not highlighted so it was hard to see. Sometimes I also picked items up (the hammer and the chicel) and didn't know what I needed them for, so I ran around and see where I could use them.
And another thing: The monster chase was fun, but at a certain point it just ignored me and I could walk in front of it and it would just keep standing there. Besides, the room where the monster came from needs a ceiling.
All in all, great story so far, keep it up!