I've discovered this little game over a year ago. But it wasn't out at the time, and then I just forgot about it. But now it's out on humblebundle.com, and if you pay 4 bucks or more you also get The Binding of Isac (by team meat) and Blocks that matter. Two games I personally have waiting on steam sales for since forever! This has to be my favorite bundle yet.

Oh... and GO BUY IT!
http://www.humblebundle.com/

This one's a hell of a deal. 3 awesome games.

Of course I already bought it.
The Binding if Isaac is just an extra bonus.

To be honest, I'm more curious about playing a game using voxels.