This is great! The web demo parses ordinary sentences with pretty good accuracy. I had to resort to twisters to confuse it:

The old man the boat. (the elderly staff positions on the boat). Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo. (see https://simple.wikipedia.org/wiki/Buffalo_buffalo_Buffalo_bu..., it's not a fair test, but it illuminates how the underlying engine works)

I'm going to point this project out to a teacher I had, see how it does with other corpora.