It was legitimately amazing in 1996. Nobody's been able to scale it or find a use for it, though. Retinal projection is how the HMD on the AH-64 Apache works and has had; thing is, that didn't exactly set the world on fire and neither the Army nor the Air Force has really reached into that bag'o'tricks since. And that's DOD money.

There's a Reality Distortion Field around VR that makes its proponents go "If we build it they will come." Thing of it is, even 3D movies are scaling back and that's the most demonstrable profit center there is.

We process 3D primarily through parallax. We create parallax primarily through moving our head around. Anything that is intended for your eyes fails. Anything that is intended for your space wins. Unfortunately, anything that's intended for your space is necessarily exclusive and takes up a lot of room.

This is 7 years old and it kicks the shit out of Oculus. And it still hasn't set the world afire.