The developers describe Prue as like having a digital bonzai tree in your pocket. You shape and direct the tree as it grows in a minimalist environment to the sound of relaxing music.
Prune was recently named by TIME Magazine as its game of the year. For more on Prune, be sure to read our impressions. There's no word yet on whether this is a permanent or temporary price cut, so you might want to pick up the game as soon as you can.
Thanks to Julien for the tip!