Although it's virtual, I really like this idea. A face-to-face pinball should be pretty basic, and this one, with its retro look, fits well with the concept.
On an electric model, the center of the field must be occupied by bumpers, and the space in front of the goal must be rather clear.
But I think that on a manual model, without any mechanical spring (slingshots / bumpers), it would be necessary to place pins in front of the goal area. Thus giving the ball a bit random trajectory.