For some reason the game will not load in the web window. I have exported it many times trying to get it to work. At the moment the only available version is windows download. Im sorry, Ill try and build a mac version here shortly
I had that same problem exporting my game to WebGL. I fixed it by going to Edit --> Project Settings --> Player --> Publishing Settings, and turning compression format to "Disabled" before building. I hope that works for you (and let me know if you get it working because I'd love to check it out)