The main goal in Osmos is simple: you, an amoeba-esque organism known as a "mote," must absorb smaller motes to become bigger. As your size increases, you are able to absorb more and more motes until you are the largest one in the area. This seems like a simple objective, and at its core it is. But, in order to propel yourself around to capture motes, you must expel a part of your own mass, which in turn decreases your size. It's a beautiful and unique game of calm strategy and intense thought.