Mac OS X issue, chmod does not seem to work.

I wasn't really able to find anything in the FAQ or any of the forum posts about my issue, and i didn't really know who to turn to, but I am really trying to play this game on Mac OS X and having a lot of difficulty. I downloaded the mac client from the website, but when I attempt to launch it, it just tells me "the file cannot be opened." I looked up the issue and a lot of peoples solutions were done through using the mac terminal and a "chmod u+x " command. I have tried every variant of it that I can, but no matter what I attempt, the file still "cannot be opened." If you have any insight on what the solution might be or are able to point me in the right direction, it would be greatly appreciated. Thank you.

you need to use a SPACE before and after the command.
How you did: "chmod u+x "
How you should do: " chmod u+x "

I do not have a Mac but that is what I got