First off, if you are reading this, haven't beaten the game and intend to... STOP!! I will be talking about the ending because I found it highly amusing, and I do not want to ruin it for you <3 If you have finished it, or spoilers do not matter to you, read on friends!
So first off, the game itself was AMAZING! I loved it. I liked how it was run, as though you'd been locked away for who knows how long, and you are trying to break out with a little robotic companion, Wheatley. His a friendly robot, with a funny British accent,and is generally helpful. Well, until he has you plug him into an electrical mainframe and you accidentally wake-up GlaDos again. Yeah... No Bueno.
So, as she's waking up, she reveals to Wheatley that you are the human