Game description from the publisher: Can you stack twelve blocks before the Stack Smasher gets to the tower and topples it? In Stack Up!, players take turns spinning a color and stacking a block. Spin a challenge, and you'll add a tricky task like stacking with one eye closed or while singing "Happy Birthday". Spin the Stack Smasher, though, and you'll be one space closer to the big topple! Can you get the blocks stacked in time? Stack Up! includes rules for three levels of play.