No dice.

Think about it, the API of Unity is widely different than the one of Gamestudio. And your quote is about using a language like C++ to interface with Gamestudio, not Lite-C interfacing with another language. And even if you could use Lite-C to interface with Unity (why would you, Lite-C is a bastard of a language), you would have to make a bridge for Unity to be usable in Lite-C, which means making their API available to it, not Gamestudios.