Looking for a mind-bending challenge beyond your favorite game, Tetris? This 639-piece lenticular puzzle features layers of Tetris tetrominos with color-shifting puzzle pieces that will keep you guessing all the way to the last piece. Want even more of a challenge? If you solve the Impossible, add on the 56 bonus pieces for an extra 9.25x 6.25 tetromino piece puzzle to add additional complexity. Once you're done, display your puzzle with the included matching poster. It's THE puzzle for Tetris fans who love a brain teaser challenge.