Nanotube is a stylish action game that tasks you with preventing an army of colored orbs from escaping the center of a circle. You have control of a wall of segments at the perimeter of that circle, and you must block each orb with a wall segment of the same color. It is a satisfying treat on many levels, with orbs flying at you with a regular rhythm and popping with a musical sproing, so if you're playing well, the game will automatically play a random tune for you.