You control a rain god, Tsuyu, who is tasked with returning water to a barren corner of the galaxy. With your powers you can make clouds spring to life and spout forth water. But make sure to avoid the dangerous denizens of the planets you are trying to save!
The game is played on a series of worlds. When you reach a copse of desiccated trees, you can rejuvenate them by holding a finger on the screen, causing rain to fall.