Tetris has had people hooked for 30 years because it appeals to the basic mental instinct to tidy things, an expert said.

The claim comes as the 30th birthday of the game, which originated in the Soviet Union, is marked today by World Tetris Day.

After analysing the addictive game, Dr Tom Stafford of Sheffield University said: "Tetris is the granddaddy of puzzle games like Candy Crush saga - the things that keep us puzzling away for hours, days and weeks.

"Tetris is pure game: there is no benefit to it, nothing to learn, no social or physical consequence. It is almost completely pointless, but keeps us coming back for more and more."

Dr Stafford says the tidying and puzzle-solving aspect of the game delivers the same kind of psychological satisfaction as scratching an itch, and that has played a large part in the game remaining popular.

Ryan King, editor-in-chief of Videogames magazine said: "Despite its age, Tetris is still the best puzzle game ever made. Only Angry Birds has come close to its simple appeal and cultural impact."