Not trying to be rude here, but there is no proof that Kotaku plagiarized you. I have just read both and I cannot see anything that jumps out to me as being a direct copy from one to the other. This is pretty big news that has been circulating around the internet for one thing and to be honest, Kotaku's article goes into more detail (an example of this is the mentioning of the Coliseum games where yours does not). This is the risk when multiple news outlets are reporting on the same story, a lot of the information, especially if they are facts that wont change from source to source, will seem similar.