In Archer Maclean's Mercury, the player tilts a level in order to get a drop of mercury to its appointed destination, in a similar fashion to Marble Madness. Differences include newer obstacles and the ability for the mercury to morph, split and transform around the levels. A sequel to Mercury has been released, entitled Mercury Meltdown. The game features new puzzles and modes, as well as a more vibrant and cartoony style of graphics. Another sequel was released only for the Wii called Mercury Meltdown Revolution. Source: Wikipedia, "Mercury (game)", available under the CC-BY-SA License.