Phlipple is a unique puzzle game. The goal of every level is to reduce a 3D shape to a single square. Elimination of squares is done by flipping edges around just like in a cardboard box.
It starts off relatively easy to teach the basics just to later on serve hours of brain tickling fun. It's a great way to train memory as well as orientation in 3D.
Awesome game! I really enjoyed it. I took me several hours to go through all the 100 levels. It personally found problems 43 and 71 very difficult relatively to the others, and it only took me one hour to finish the last 29 problems. So I wouldn't say the difficulty is strictly incremental, as stated in the game description; but it is subjective and can also be a matter of luck. I definitely recommend it to anyone who's interested in visualization, planning or logic.