First, find a box to make the frame of the game and two small dowels to create the rolling background. Those dowels are controlled by a motor that turns on when I presses a blue start button. Then attach another motor to a popsicle stick that opens and closes the box at the beginning and end of every session.
The Flappy Bird itself contains a magnetic sensor called a reed switch, which is programmed to be in a continual downward motion until you tap the button (just like the smartphone version). When the magnetic sensor touches the magnet — which is taped behind the pipes — the game is over.
The Arduino sketch is available here: https://www.dropbox.com/sh/ch0s13n480l2sph/-WJIdfY_hD
There’s also the opportunity to expand upon the physical game idea, creating your own new games to include in the box through the use of templates. I created a race car game inspired from Frogger and Pole Position.