Just suggestions for 3D elements
Lighting System
Something like Crossy Road level (see image below) is good enough. It's OK to have a very simplified 3D features, but without lighting 3D is of little use. The solution currently is to either aim for a specific art style or by making your texture a specific way to simulate that (though the latter would lose its effectiveness once the object is rotated)
Supporting one Directional Light (like Sun) is good enough at this point.
3D Shape Rotation
3D Models can be rotated so should 3D Shapes?
Thanks.