Dustin and I tried random symbols and came up with some interesting stuff, but when we stumbled across using emoticons it just took off. It seemed a good fit for what we were trying to do. Unfortunately, there's some excess to keep every line a smiley, but, nonetheless, it seemed to work out.
So, thus was born EMO. It's not complete, so as we change it and update it we'll make the changes here.
Yes, we know there's someone out there who wrote a higher level language using all emoticons, but we found it after the fact so we weren't too concerned with the un-originality of this.