Creeper World 2 is a sort-of sequel to Creeper World. (Read that review for some basic information. Also, note that the link is to a specific variant of the game and that there's probably a bunch of variants out there.)
It has a significant gameplay change from the original, although it also is quite similar.
The Creeper still flows downhill (most of the time-ironically, the screenshot represents a time where that isn't the case), but "downhill" is now, well, down.
That's right, it's no longer top-down but a sidescrolling game of sorts.
Your home base this time is a ship that has been tasked with wiping out the Creeper. Apparently, in the time since the first game humankind's technology and knowledge of the Creeper have both advanced, and instead of being forced to fight a battle for survival, you can destroy the Creeper's emitters, which had once been thought indestructible.
More features are added to gameplay, including "anti-Creeper" which you produce yourself, enemy drones, and others, while old features have been changed-for instance, your base now generates "wireless packets" so that you don't have to worry about connections, just relay devices called beacons. I have to admit that being able to make a "friendly" version of the Creeper is a great addition-it's much easier to track the danger level when you have your own field of control that cushions you. (As one might expect, Creeper and anti-Creeper are mutually annihilating.)
There are also variable gameplay paradigms. Probably the most entertaining of these is the "zero G" environment (an example of which is shown above) where the Creeper tends to move around chaotically and cling to objects instead of flowing down predictably.
While I don't know if I like this game as well or better than Creeper World (which I like quite a lot), it's a fun little game so far, and you could find plenty of worse games. I can recommend it.