Demise is a hard game because aside from shooting floating robo-things, you have to not puke. It’s an FPS that shows you everything around you at the same time: an entire 360 degree view mapped onto one screen.
For whatever reason you can only play Demise with a controller, and the slightest pressure on the analog stick swiftly spins the bulbous grey hallways around your head, signaling to your stomach that the deities have forsaken humanity and the digestive organ rebellion has begun. I played two hours of Half-Life 2 on an Oculus Rift DK1 and felt fine. It took two minutes before I was hammering Esc—ineffectively—to try to make Demise go away.
If you’re up for the challenge, it’s a cool idea, albeit one I and I’m sure others have experimented with by cranking the FOV up in old shooters—not quite the same thing, but with similar gut trouble. (This is how cool people play Quake 2.)