From Wikipedia: Mercury Meltdown is a puzzle-platform game for the PlayStation Portable. It is the sequel to Archer Maclean's Mercury. Like the first game, the goal is to tilt the stage in order to navigate one or more blobs of mercury to the destination. In contrast to the original, Ignition Banbury had more time and experience developing the game and listened to player feedback, allowing the game to be easier and provide players with more freedom to choose levels. The game has new hazards, enemies, and minigames.