From the publisher:'Brain Twister! is the only double-sided memory game in the world. Designed by master puzzle-maker Klaus Schroer, Brain Twister! offers a unique twist on the classic matching game: both the front and back images of each playing tile must be matched in order to score. Brain Twister! features educational and scientific artwork that will appeal to players of all ages.'Brain Twister offers a unique twist on the classic memory matching game. The Discovery Channel version of the game features 90 double-sided tiles with fascinating images from across the universe including the Space Shuttle Endeavour, a remnant of a supernova, and the International Space Station. - BoardGameGeek