Solar 2 is a game that you probably won't play for hours at a time but will keep coming back to over and over again.
Even though at a glace the game may seem like Feeding Frenzy in space it has a lot more to it than that. Rather, Solar 2 is an open world game where you play as a celestial object. You start as the low man on the totem pole (an asteroid) and work your way up to a mighty black hole. The way you go about doing this is gathering mass and slowly working your way through the level progression (asteroid, planet, star, black hole).
Gameplay wise there's nothing to really write home about. As an asteroid you smash into other asteroids, as a planet you gather asteroids in your field of gravity, and as a star you gather planets that you then gather asteroids with. The game is simple but feels polished enough to feel like you're getting your money's worth. You have great control while flying through space and the momentum and inertia feel just right. The music is nice and relaxing which is a really great fit for this type of game.
You can also take on missions given to you by a mysterious entity but they offer no real rewards as far as I can tell (other than achievements) so I never felt compelled to do them.
Simple and solid gameplay, and Great presentation are really what define this game for me. Not a whole lot there but what is there feels good and is definitely worth spending some time with.
Protip: only $5 on XBLIG while it's $10 on Steam. I own both but if you're a real cheapskate then you know where to go.