Actually, how are you planning this exactly?
You mentioned skype.
So you are planning to run this on your computer and the others are just having skype without seeing it on the computer? Or do they see it on the computer? Because I am not sure if you can run it and everybody sees your screen. You would be the only one to enter stuff in this scenario. You would enter by mouse. You would be the game master then.
There are ways to program multiplayer games in processing but that’s over my head.