Most prolific puzzle videogame series

Tetris is the most prolific puzzle game series of all time. Early license disputes make it hard to pin down an official total, but at least 50 games have carried the Tetris name, beginning with Alexey Pajitnov's 1984 original. That number triples if localized versions, grey-area licensed copies and unofficial games inspired by the Tetris formula are added into the mix.