The Untold Engine is licensed under the LGPL v2.1. This means that if you develop a game using the Untold Engine, you do not need to open source your game. However, if you create a derivative of the Untold Engine, then you must apply the rules stated in the LGPL v2.1. That is, you must open source the derivative work.
It took me five years to develop the Untold Engine. So, do not remove my name from the files :).