Japanese developer historia Inc. has recently published Dungeon & Burglar for iOS/Android powered by Unreal Engine 4! It's an action game where you are a thief and have to learn how to play by dying.
Dungeon & Burglar is a full-3D action game. You'll go deeper and deeper into the dungeon to get treasures. Though having a light-hearted appearance, the game is punishing like any good old-fashioned easy-to-die game with a serious feeling of accomplishment upon success.
The game was produced with a policy where one creator could create one title his/her own way. This was a challenge where "a small team should develop a mobile game powered by Unreal Engine 4 at a low cost in a short period of time." Though that sounds like a reckless endeavor, it was indeed possible for a single artist to release the game after around only one month of development by taking advantage of Blueprint scripting in Unreal Engine 4 and assets available in Marketplace without programming any code.
The technical artist resposible for the game has written a development diary for the experience in historia's blog. Also, there are articles there that describe the technology of Unreal Engine 4. Check out the blog!
Enjoy the game!