In Solar 2 you play as a part of the universe in the form of an asteroid. As an asteroid you travel around the universe colliding with other asteroids to gain mass and eventually become a planet, grow life on yourself and produce a space faring civilization, because a star and found a solar system with possibly multiple space faring civilizations, and eventually become a black hole and suck up all the matter in the universe.
The controls and gameplay are extremely simple, you literately only direct your planet/asteroid/star on one big endless 2D plain as you try to gain mass either by bumping into other asteroids as one your self, anything as a black hole, or by getting other smaller masses to orbit you. It is that simple, and over far to quickly, but it is an enjoyable and unique experience while it lasts.
My mini-review of Solar 2.