KTML5 I think you may have been mistaken as Unreal Engine 4 uses C++ source code.
O.o Yeah, the source itself is C++. Pretty much every engines source is C++. You can tell just by looking at C2 that is was probably developed with C++ inside Visual Studio, just as much as you can see it in UE4.
I meant that the game programming is optionally visual programming. It's called Blueprints and is just as, if not more, useful and easy as Construct 2's programming interface. You should try it out if you haven't.