Edge is a puzzle game developed by Mobigame for the iOS devices. Originally released on the iTunes App Store in December 2008, it has been removed and re-added to the store multiple times due to a trademark dispute with Tim Langdell of Edge Games, concerning the use of the word "Edge" in the title. The game was released on PlayStation Minis in Europe and Australia on December 2, 2010 and September 20, 2011 in North America. The game was released on Steam on August 11, 2011 and on Android along with Edge Extended on January 31, 2012, as part of the first Android Humble Indie Bundle, followed by a release on Wii U on November 21, 2013. Edge was also released for the Nintendo 3DS on December 26, 2013.GameplayThe gameplay involves guiding a cube around 48 levels (the three last levels have to be unlocked by taking all the prisms in the 45 previous levels) collecting coloured prisms by dragging the finger across a touch screen (or using analogue controls on PC and Wii U), taking care not to fall off the paths. By dragging hard enough, the player can make the cube climb over steps. By balancing the cube along the edge of a wall or space, players can hang across certain edges in order to cross large gaps. In addition to dragging, the game can be controlled by on-screen keys or the iPhone's tilt-sensing accellerometer. Certain areas will cause the cube to shrink, allowing it to fit into smaller gaps and climb up walls. Collecting all prisms in a level and clearing it quickly earns players an S rank.