I remember, and I still think, that one cannot even make a prototyped 3D game to test just simple behaviors without using gigantic tools like unity or knowing extensive C++ programming, design pattern, a decent or basic 3D engine, etc.
Now I'm wondering, since I know programming, that I'm still more lucky that the ones who need to learn programming prior to know how to make something: even scripted engines such as unity are not for kids, and to my sense they tend to dictate their ways of doing things, which is not the case with engine like ogre or irrlicht.
I remember toying a little with the blender game engine, it was possible to link states or something I don't remember very well.
Now I'm thinking that character driven games occupies a big part of the game market. Do you think it is a good idea to make a character-controlled oriented game engine which allows only to build AI instead of anything else ?