Right: so instead of using a joystick, you'll be using a Cyclops-like visor that'll cost about $400 for looking around (this kind of technology isn't going to be cheap). Y'know, joysticks are included in game controllers for no extra charge; or does the C-stick get replaced by the visor? And those are also included in game controllers with no extra charge... Anyway, explain to me how you'll be able to walk in the game if you can't stand up with this thing. And if you could stand up with it, would you have to walk in place? Or does the camera automatically move in the direction you're facing? And about props: I'd feel pretty weird if I were holding my hands up in a certain way to cradle the virtual machete. And then I'd have to swipe my hands every which way to get better results when killing somebody.
Or how about this: the joystick is used for moving, but the visor is used for managing the items in Iron Man's suit. Y'know, you've got targeting, weapons selection, cell phone; and then there are repulsors which you shoot out of your hand. And you expect to do this sitting down? Iron Man doesn't sit down; can you see Iron Man sitting in a chair and shooting repulsor beams and missiles at the enemy? Now that's virtual reality. I guess this rules out Mario games since you've got to jump an awful lot: both to get coins and defeat enemies. And don't forget the triple jumps, wall jumps, and spinning in SMG; yikes. I suppose a more realistic scenario would be standing at the bottom of the pool and looking around while "holding" a machete and then wait for a jellyfish to come.
I think you're equating immersion to complete obliviousness to the world around you. And this visor will make it really easy. Y'know, because, well, it's a virtual reality visor. Now, I didn't say all this to insult you; I'm trying to generate some thought about this while trying not to sound stupid myself.
My concept would be just to use the joystick(s) and buttons to walk, jump and maneuver, kick (basically anything that has to do with your legs) This, yes, because you would end up oblivious to your
real surroundings so really standing up would be dangerous (unless they also mounted a couple of cameras on the visor to overlay your real surroundings and make it more of an augmented reality than virtual reality ... but that would both add to the probably already expensive price AND be kind of confusing to have to make out BOTH your virtual world AND your real one)
The other extreme would be using something like this on the XB1 with the kinect, standing, jumping, running in place to move (because, again, really walking spells hazard when you can't really see.) and that, to me just sounds awkward, tiresome, and a sure recipe for motion sickness.
Arm/hand movement, on the other hand, like holding a machete or other similar item doesn't seem all that strange to me. If Skyward Sword was any indication, it's probably far MORE natural than button mashing (or primitive wiimote waggling) and natural is what I'd be going for.
and, yes, this would probably be a rather expensive little toy but hopefully an optional accessory that most games could support (even if it was with a patch) by mapping the camera to head movement and separating weapon sights from camera control.
Also, speaking of controls, one interesting aspect is also that no auto aim mechanisms would work as well as built-in martial arts abilities and things like that. If it's based on your real movements, it's also a bit more based on your real skills and coordination, which could be a downside.
While first person would be the most obvious choice, I think it could also be done with 3rd person games (using a more traditional controller) but the developers would have to be a little more careful with camera angles, maybe have the camera still rotate/float around the game character but always facing the same direction and leave the actual ANGLE of the camera to the the person's head (at least vertically) to avoid having a motion sick gamer puking in his helmet, so to speak.
It would definitely have to be done right and it's probably not an easy fit for many pre-existing games right out of the box but if it's done right I still think it could be a great enhancement to the game experience that would be well worth the price as an optional addon.