Portal = Beaten
I just finished it a few minutes ago. I need to go back through and get all the achievements and beat all the bonus stuff, but I've played through the main storyline. I think I did it all in under 6 hours. It took, like, 4 or 5 tries to beat GLaDOS. I almost ran out of time on the last attempt. I think I had 10 seconds to spare when I finally burned that mother up.