Portal: Overheating Xbox 360
Play the level where you face off with the laser guided robots. Once you get past the first few robots, you must start dropping the boxes on the robots heads so that they fall over. In the little place that you find the first two boxes, crouch and walk behind where the boxes were. You will find a little room with odd music playing and graffiti on the walls that says things such as "The cake is a liar". There also seems to be an Xbox 360 with a pot inside of it. The Xbox 360 is overheating and boiling the water.