You start with 5 buttons. 4 with colours and 1 start button.
Once you press the start button/ any key on your keyboard, one of the 4 coloured buttons with flash . You have to click on the same colour. If you do the previous step correctly then again one of the 4 coloured buttons will flash.
You will now have to press/click 2 buttons in the correct order (1st button that u pressed last time and 2nd button which flashed this round)
Repeat these steps and enjoy your game!