Punch-Out!! was always staged like a boxing match seen from the audience. In 3dSen the ring becomes the actual setting — a fully 3D-modeled square, ropes and all, with Mario the referee inside the ring with you, walking back and forth as he counts. Little Mac stands at the front of the ring and the opponent stands at the back, and when either of them throws a punch they actually move toward each other across the canvas to make contact.
Because the ring is real space, the camera can do something the original game never could. When you get knocked down, the view drops to the mat. You're looking up at your opponent taunting you from above, with Mario standing next to your head and counting. It's a perspective you can put yourself in once just to see it works — not a tactical advantage, just a thing that's now possible because the ring has a third dimension.
The VR version is the one that crosses into different territory. Beyond rendering the ring in stereoscopic 3D, it ships full motion controls for the whole fighting moveset. You throw a straight punch forward for a body blow, raise the punch at an angle for a face shot. You dodge by leaning your head left and right, and duck by squatting down. You block by holding both hands up in front of your face. To trigger a star punch, you push both hands straight out at the same time. None of this is mapped to a button — it's read from where your hands and head actually are.
Playing this way is physical. One reviewer described being sore the day after — sweating, side aching from leaning into dodges, surprised at how much real boxing this turns out to involve. There's an honest trade-off to flag: leans and ducks can occasionally be misread when you mean one and the system sees the other, and that matters in the later fights where dodging-then-countering is the only way to land hits. As a fallback, the standard buttons on the controller still work (A and B map to face and body punches), so you can mix motion with buttons when the timing has to be exact. The design goal is full motion control, and most of the moveset gets there.
The gameplay logic underneath is the original 1987 NES code, untouched. Same patterns, same windows, same tells. What changes is that you're now reading them with your body instead of your thumb. To use motion controls on a Quest headset, connect via Steam Link or run wired through Steam.