My internet was down earlier today and it wouldn't let me play offline.

I had the same exact problem (Thanks Comcast!), and not being able to play a stand alone game was entirely unacceptable.

  It's not a bug.  As pointed out here (https://forums.elementalgame.com/400368) the beta requires an internet connection to play.  The reason for that is that we are able to make a lot of changes on our side to fix things without having to release a patch (since you are running online).  The public version won't require an internet connection to play.  This is the same process we used for the beta before Elemental was released.