Nice intro. Great job. Loading a mesh should be just as easy since the cube is a mesh as well. But, it is better to have 3D modeling tool to build the mesh. Even with VS:Pro Mesh Editor, I don't think it will be as good as dedicated software for it.
I have Chimpact on my phone. It is indeed gorgeous. I don't even know how they compose the background, it should use basic template and added the effects for field of depth. But, I just couldn't figure out how they connect those trunks and apply those effects so flawlessly.