The Unreal Engine is a very powerful game engine developed by Epic Games, initially designed for first-person shooters. It has been proven successful in supporting a host of other genres, including stealth, MMORPGs, and action RPGs over the years.
The company currently has a working implementation for iOS and Android, and it has been used in a number of hit games, such as XCOM: Enemy Unknown.
Unfortunately, despite supporting some great game engines like Unity or HAVOK, it does not appear the Unreal game Engine will be hitting Windows Phone any time soon.
Tim Sweeny, the founder of Epic, has said in a forum thread on the company’s website that that the company has been working in that direction, in particular WinRT API support, and that they expected this eventually to come to Windows Phone, but that they were focussing their efforts on iOS and Android.
It seems the Windows Phone population will need to grow a bit more before port can be made a priority.