Using a 3D sphere in 2D space

I'm making a basic scene in unity, which has a sphere against a plane, and the sphere moves around randomly.

The problem I'm facing is that, the camera is looking at the center of the plane, so when the sphere moves from side to side, its shape contorts due to the camera's perception. How can I do away with that, so that as the sphere moves, it remains the same shape as it would be when its right under the camera?

Use a camera with orthogonal projection. Another way would be to create a texture out of your sphere and render it as a sprite. It depends...

Change the property of camera "Project" to "Orthographic".