Really liking this puzzle game. Simple mechanics but enough to provide some wickedly thoughtful problems to solve. Includes a level creator with the ability to share your creations with other players via twitter, and obviously you can try out other's creations too. (( Haven't tried this feature yet - but the implication is that there could be tons of extra content available besides the Dev's original 60+ levels )) Unfortunately you need to have a twitter account to access them, apparently. Enjoy! Well worth a dollar.
