It features long-range LED eyes and movable arms. 

The circuit you created, by connecting the battery holder to the gearbox and the robot's head, allows the smooth flow of electric current when the battery is activated.

The "ON" switch activates the circuit and allows the electric current to flow to the gearbox and the robot's eyes, bringing the Crazy Robot to life.

This happens because a battery always has two poles, a positive and a negative. At the positive pole, there are very few electrons, while there are many electrons at the negative pole.

 If the positive and negative poles are connected, the electrons move to correct the imbalance, creating an electric current. The robot's head and gearbox can then convert the energy from the electric current into motion and light.