I have no idea how this rated so low on vibes, I thought it conveyed snakes and oozing darkness the whole way through. The title for Room 9 seemed to disappear, but otherwise I love the font and the way you laid things out, though perhaps indented bullets might have made the subjects of each room stick out more?
I worry that having to make a Viperian Countdown check every 3 rounds in addition to normal encounter rolls might be a bit too much busywork for the GM.
But overall a nice classic adventure that I felt was laid out well and fit the intended themes. Good job!