http://evevalkyrie.com

Best practices for VR, from seven devs working with the Oculus Rift
▻http://www.gamasutra.com/view/feature/203438/best_practices_for_vr_from_seven_.php

Simulation sickness is a very hard problem to solve, and will probably be one of the biggest issues to fix before we’ll see broad adoption of VR hardware in the next few years. The cause of it is the brain getting mixed signals about movement but not feeling any force.
In Valkyrie we’ve mitigated this problem in a few ways. Having a static cockpit around you, as well as a visible first person avatar helps ground you in the scene. Also having a constant forward momentum and not doing big sudden changes to velocity. As an example - If you go from 0 to 60 Km/hour in a fraction of a second, you will feel like you were kicked in the back.
Latency is another thing to keep a close eye on. When you turn your head the amount of pixels being shifted in one frame can get quite large, and this grows even larger when the framerate drops below 60 fps. This causes a noticeable lag between what you are seeing and what the brain believes you should be seeing, which causes simulation sickness. I agree with Carmack that we need to sacrifice some visual fidelity for a higher framerate, since it’s a choice between being able to play the game comfortably and some eye candy. (Gunnarsson, working on Eve Valkyrie ▻http://evevalkyrie.com)