@Paul_L_Ming:
The problem : C4 need lot more programming, and even C++.

In fact Unity Indie can do it very well depending on your project type and size.

Imagine some Mario Galaxy style game : the art, and simple texture effects make all the difference.
Could be done in Unity Indie ,no need for full screen effects or shadows (simple rounded shadows would do it).
Any casual game can be done with Indie, with subttle effects you can do great things, and the casual game market is growing really big

The templates for collision,cameras are really good and you can use them by a click, to very quickly prototype (before tweaking them or doing your own camera).
Unity is also fast to use as 3DGS ,and more friendly (editor for all things all in one).