I agree with the previous reviewer. If you follow this adventure as written, your players will feel railroaded since it is primarily a plot point encounter. Add some spooky bits and a few more small beasties and this has paranoid rat trap written all over it.
Considering this is only a dollar one really can not complain. There is material within that is workable; the diagrams are rather nicely done for instance. That said, it is not ready to play straight from the download. The GM will need to spend a lot of time considering what she wants to have happen and then write in that material to make this really playable.