A very good way to make a non-linear mission in a limited environment. The oppressive feeling of being stuck in the "same" room no matter what exit you take works really well for a paranormal-heavy scenario.
The fact that every room variant is detailed and named appropriately and that a map is here to guide the GM to the progression is really nice.
Progression is costly as entering a new variant will invariably trigger a random encounter/event with various effects, some rather heavy. Thinking and noting details and clues is recommended to get to the end with minimal loss.
Overall, the mission fits on a 2 page PDF and it doesn't need more.