Who wouldn’t like to be able to take their favorite game anywhere? There’s always been a whole range of games designed to be able to travel with us. At first, these games were powered manually by the player, or by force of gravity. Later, wind-up mechanisms were introduced.
The breakthrough came with the electrical batteries. In the beginning, they powered the mechanisms and motors. Later, in portable games, electronics screens gained popularity, and the games themselves became more and more feature-rich, slowly evolving into miniature versions of stationary video consoles.