Where the Rubik's Cube is solved by twisting blocky columns in intricate patterns and sequences, the Magic Cube design is a much ... that's reckoned good for up to 2.5 hours per charge.

designers have completed what is now the official Guinness World Record holder for the “smallest rotating puzzle cube.” But even at just 0.5 cm (0.19 in) wide, the miniscule Rubik’s is ...