Unity engine is a multi platform game development tool used by new game developers.From 2013 Unity games became more popular with titles like Kerbal Space Program, Cities Skylines and the most recent one: Firewatch.
https://www.youtube.com/watch?v=kZX3MgsRb0A
Unity is compatible with a lot of programing languages such as:C# and JavaScript. Even though is not as used for triple A games as other engine like: Unreal Engine, Frostbite Engine or Cryengine, is really good for new game developers and can do some amazing graphical effects either in 3D or 2D.
Gata