*Update* – If you are running the DVD version and don’t need a connection to the Internet to have the game verified, try disconnecting from the Internet and play off-line.
It seems that Mac users are experiencing an issue with their games as of today. If you have encountered the “Can’t Start Game Process” issue, head over to this post and add your input. Crinrict has put together a list of information for you to add to your post.