This anniversary edition keeps the basic design and retro technology of the original Tamagotchi, but the updated ovoid gets a smaller screen (16 x 16 pixels vs 32 for the original).

Available in six colors, the compact egg-shaped keychain still has the same features as the original model, and still involves feeding, cleaning and playing with a pocket-sized virtual pet to keep it alive.

Released in 1996 in Japan and in 1997 in Western markets, the Tamagotchi was a schoolyard sensation, with 82 million of the virtual pets sold. Each egg-shaped keychain had a small screen displaying a digital creature that the owner had to take care of to keep it alive and well. Neglecting the pet caused it to die.

A limited number of the mini 20th-anniversary edition models will go on sale in the USA from November 5, priced $15 each.