I was demoed Hawken and while sitting in the cockpit and looking around felt perfectly normal (and amazing), as soon as I started walking I felt uneasy.
Mind you, I’ve been playing playing UT and the like for ages and never had motion sickness problems – so that wasn’t it. Rather, I physically felt a disconnect between what I’m seeing and what I’m feeling. Without the edge of a monitor to ground myself, it felt like someone grabbed my head and started dragging it around.
I was asked to jetpack up, look down, and then free fall – and I definitely felt something when I landed. I felt like my body should shake but it didn’t, and I literally started feeling sick from that point on.
I took it easy after that – walked around a lot, made sure to land soft if I jetpack, and even then I had to take a break soon and I later found out that I lasted only like 5 minutes, and that was considered “longer than usual”. I had that carsick/seasick feeling for like an hour afterwards. I was told that with practice, you can pretty quickly train yourself to be able to play without physical symptoms.
This isn’t meant to be discouraging in any way – the experience was amazingsauce and I’d definitely buy a Rift when the consumer model comes out – but I don’t think humans are naturally designed to deal with this sort of complete sensory replacement. If anything, the Rift is doing its job a little too well. I have a feeling most of their effort right now is focused toward solving the human side of the problem, because hardware wise even the dev kit was totally ready for sale.