Next time you receive a game request notification simply click the notification globe icon. Next hover your mouse over the top right corner of the undesired notification. An “x” should become visible with the caption “Turn Off” . Click on this “x” and you will be presented with an option to turn off notifications for the particular game. While this may not be the best solution it does help if you receive annoying requests for the same games over and over and you have no desire to play them.