Asspop, you have to press X, Y, Z, Z, Y, Shift+Enter (make sure you hold shift while pressing enter), and finally let go of Shift and press Enter. Make sure the Minesweeper window is selected and your mouse is over it
kind of like the dorks who used to say the konami code was up up down down left right left right SELECT start when in fact you don't need to push select at all.