I doubt XNA based Opengl ES will be efficient. If I were a game developer, I'd rather rewrite my code. The Game problem can be solved with game engines. But I'

I doubt XNA based Opengl ES will be efficient. If I were a game developer, I'd rather rewrite my code. The Game problem can be solved with game engines. But I'd like to write opengl directly. As for UI, Qt for android is a good approach.