Thanks alot for giving it a go! I'm sorry about the mac build, I don't own a mac to give it a go, there were just a few people asking about them (I think you may well have been one of them) so I did the build and put it up. I wonder whether its similar to the webGL build, where certain features used just wouldn't work when built that way.
I have to admit, I was considering making the guards vision a bit better, but I didn't want to make the game too difficult. Its certainly something I can try in the future.
Thanks again!