I don't use a Mac, so I am not sure how different the file directory is, but you should be able to go into steam and find your library folder (Click Steam at the top left of the main Steam window > Settings > Downloads > Steam Library Folders). It will show where steam installs its games. Not exactl...

First of all, I would like to say I am incredibly impressed with the pre-alpha. So far I have played/tested 10 hours (It's my day off, and I was excited), and so far the biggest bug I have encountered is that some seeds just flat out do not allow you to progress. For example, in seed 5FF9D9F7 , the ...