Let the cars through the crossroads by controlling the traffic lights.
Control which lanes get a green light by orienting the crossroad cards. (tags 1, 3, 4, 5)
Coordinate the lights to get all cars through in the shortest time possible.
Don't let (too many) cars crash!
Reset the game by showing the reset card. (tag 2)
This game is played on a surface, with the webcam pointing down.