The basis of Operation is a simple circuit with an LED, a vibrating motor, and a buzzer. When you close the circuit, the components do their thing.
However, for kids who are not used to working with circuits, it's a little hard to picture what's going on. The sample circuit here makes it a little clearer:
The gameboard works the same way -- but in that case, the positive piece of foil is attached to the inside of the box, and the negative piece of foil is attached to the outside of the box.
To connect them and close the circuit, you touch the tweezer wire to the inside foil where it comes up through the openings in the top of the box.
It's a little convoluted, but it works!