Solar 2 is actually an indie title made and published by Murudai. You can find it on steam for 8.99 €. It's claimed to be causal so let us take a closer look.
The basic idea of the game is mesmerizing: You're an asteroid that is trying to grow to the point you become a black hole, a black hole being a super compressed piece of matter that can suck up light with its sheer gravitational pull. Now, you go through all of the stages in the creation of a star apparently. First, you're an asteroid, trying to crash into other asteroids and grow larger until you become a full fledged planet. When you're a planet you cannot crash into things anymore which is sad because that's the first point in the game where you have enough mass to actually pull objects into you. Instead you need to cruise next to asteroids and get them into orbit. When you manage to do that you will need to absorb them in a very different fashion and it's going to be your main way of playing the game from that point forward. Eventually, when you gain enough mass - life will grow on the planet and defend you against asteroids that you want to suck up.
Eventually you become a star and here is where the main game begins. Being a star, you can gather planets into orbit, who can incidentally gain asteroids into their orbit and life as well. They can grow to become starts as well and then your lone star becomes a double star. Gaining another star is a lot like gaining another life of sorts. You can slam into other stars with the star and your mass grows, but you can never have more than 10 planets in orbit at once. After becoming a star, you become a neutron star eventually.. in my opinion the most boring part of the game as a neutron star is nothing more than a heavier star that is also weaker in health and can have fewer planets.
What can you say about this game? There's humor in it and it's very sandboxy but like all sandbox games it has a timer of how long it can last before it all 'gets old'. That timer was for me only two evenings. Almost all other mainstream games only last that long too until their story is done but after Minecraft I expect a little more from my indie titles still. Somewhat of a let down but good enough for the low price of 8.99... I guess you get what you pay for.