This physics-based puzzle game from developer Curve Studios revolves around the player controlling water in all of its forms. The game takes place inside an encyclopedia known as the Aquaticus which has been taken over by an insidious dark substance. To purge the evil, the player must collect Rainbow Drops spread out over 4 different worlds. Similar to Super Mario 64, the worlds are very large and open, and each time the player collects a Rainbow Drop, they are returned to the start of the world. Certain areas require a prerequisite number of Rainbow Drops to access, and exploration is encouraged.
As Rainbow Drops are collected and the game progresses, the player unlocks various new powers for the different states of matter. The liquid mode is controlled via tilting the game world (by tilting the Wii remote) and using gravity to affect which direction the water is moving. The water moves very using realistically, breaking up into smaller droplets and waving over the other objects in the world. In the ice mode, the player can stick to platforms, and weigh down switches and break through walls due to the solid form's greater density. In the vapor mode, you play as a cloud and can freely traverse your way across the air. You have a few tricks in this mode, such as using lightning to strike objects in the world (for powering machines, attacking enemies, etc.) and blowing wind.