sentences:  "NightSky", a physics-based puzzle platformer, was released on 6 January 2011.The game had a long development history; first announced in 2007, it was known variously as "Skymning" and "Night Game".On 5 May 2008, Nygren released three minigames that were going to be part of the project, but were abandoned due to incompatibilities with the new engine.