Great game. I have some complaints, however:
The mouse controls not only your movement, but your view. This makes it slightly confusing and somewhat hard to control. The moons were a great idea, but they need SOME adjustment, since most of the time they end up hitting the planet that are small enough to eat, shrinking them and making it harder to grow.
Other than that, it was a very fun game. The graphics were better than the first game, and you added music this time. The fact that you don't die instantly whenever you touch a bigger planet is a nice addition, and it helps make the game a little easier.