P.S. : The bugs will be fixed soon. For now, To use the metro-screen, please click on the bottom-left of the screen and the Start button appears. Then click on it.
I, PPCMD, would like to thank the Scratch Team and @Raph54. I actually have Windows 8.1 on my laptop. I was a bit fond of windows 8, so I re-mixed the original project : https://scratch.mit.edu/projects/41594752/