Smart locking safe
Twisted Plastic (RC cars)
The Glove
Light-based communication
Smart mirror
Arithmetic and athletic battle
Nerf turret system
OG futbol squad
Team Rocket (more soccer)
Inverse pendulum (self-balancing vehicle)
Power board--powered skateboard.
Team Spy--nerf turret
Automatic checkers
Super tank blitz
Finger Beatz
Rubik's cube
Smart following and IMU controlled robot
Lightsaber combat
Robot lasertag