Since it is designed for a 2D Enviroment and for reach maximum performance must sacrifice some things. This limitations are:
*)Only works in X and Y axes, as a regular 2D enviroment. Don’t support Top view like scenarios (ZY). Neither allow exchange between X → Z or Y → Z.
*)Only allow rotations in Z Axis.
*)Don’t allow 2DDL GameObject scaling, use radius property instead.
*)Don’t support Unity 3D Colliders.
*)Only Work with concave 2D colliders.
*) Don’t allow Interpolation on rigidBody2D. (See example Light with physics).