MCN Pong is a marker based Pong clone that I developed together with two friends at university for a course called Lab Project: Tabletop Interaction. The complete game can be controlled by specially constructed widgets. There are two additional widgets for controlling the in game menu, which can be used to change the number of rounds and levels. MCN Pong features levels of various difficulties.
In the case that no camera is available, keyboard input can be used instead of marker tracking.