The Dink Network

It is possible to make a two player Dink game. It just won’t be easily possible to let other players go to different screens. What would be possible is to make for example some fighting buddy for dink that's controlled by other buttons so you would play together on the same computer. When Dink would leave the screen the fighting buddy would appear together with dink like the summon spell from Rabidwolf9. So is someone able to do something like this because I don't know how to change the buttons to control such a character.