I'd be interested to know how simple you can make the graphics and still have a good experience. Isn't there an inherent problem with VR that if you try to compete with state of the art non-VR graphics, you're always going to need a more powerful machine for VR than you need for non-VR (e.g. larger field of view, two screens, higher FPS)? The problem will only increase as the headset Field of View increases.
Very simple graphics with flawless 75fps+ and very little lag is highly preferable to dropping frames in a complex scene. In fact Minecraft is a case in point - it works great in VR!
