The Heat Sensitive Mugs for tea and Coffee are great canvas's for the favorite games that we grew up with. . When cool, the mugs have empty mazes on them. These mugs have shapes appearing on them when you pour hot tea or coffee into them. As you do so, you look at them and get lost in your memories of playing Pacman and Space Invaders. A warm cup of tea, and your favorite memories of the classic games make for an awesome tea time.