When I realized how much I rely on checking my phone as I get ready in the morning, I decided to create a "smart" ambient display behind a mirror, so I could get the information I want without interrupting my routine.
I built a foam-board frame for a piece of 2-way mirror acrylic that would let light through but also function as a mirror. Using an Arduino Uno, a 16x32 LED matrix, and a proximity/light sensor, I designed the mirror to detect light change from hand swipes to switch between different information displays. I used Python and an API to pull live weather updates from weather.com and pass data about weather, date/day, and time through the serial port to the Arduino.
Players control their dots with two potentiometers that control movement up/down and left/right. The player controlling the bigger dot wins if he catches the small dot and the player controlling the small dot wins if he avoids the bigger dot for 10 seconds.
This game is the first project I did in Arduino or using hardware. I wanted to make a multi-player game to maximize fun for the players, but the small and monochromatic matrix provided a challenging design constraint. So, the players' characters are differentiated only by 1 or 2 dots on the matrix, and they are able to move quickly across the screen for exciting gameplay.