This game would best be on a wii or iphone, something with tilt/motion sensing capabilities.
Have a maze filled with items that have different densities. Your character is wearing scuba gear and is very mobile underwater, however your gear is so heavy you can’t swim. You can walk and jump though. You are able to control taps that will release certain liquids into the maze (liquids of different densities) as well as to release the water.
To get through the maze you will need an understanding of which objects float and sink in what liquid. Eg, to raise a heavy platfrom to where you are, you can release just enough mercury that would be dense enough to lift the platform to you. Then you can pour in a lighter liquid like glycerine to raise another platform further, so you can jump onto the new platform. You are able to drain liquids at any time, as well as control the amount to drain. The objects will float and sink correspondingly.
