Dear Lesley

Simply download the RAR file, unzip it, and run the .exe file as is.
Some things to remember...

- This game relies heavily on binaural audio, be sure to use (good) headphones while playing. You can try playing with compact headphones or earbuds, but your results may vary. You should be able to clearly pin point the source of sounds. 

- Go slowly, and listen. The audio around you will tell you where to head next.