Not gonna lie I've thought about it, the guns and biotics could be really good as you said and the whole mission could be to survive on earth until help arrives. You're a civilian or soldier or whatever sneaking around london while it is occupied by reapers and trying to find supplies for the soldiers. You find imprisoned people and try to help them, after leading them to your hideout the indoctrinated ones report to the reapers and you then have a horde style defense of the base while people evacuate and then you flee yourself. The whole game is a survival game with scary up close moments with husks and brutes and the rachni thingos (i hate horror so id probably be too scared). Then in the 2nd last mission you see the citadel appear in space (would you need binoculars to see it?) and when night comes you see a giant space battle above you and then the transports coming down to land in london. You move with Captain Anderson to help free London from reaper control. Easter egg being that you get to see shephard and/or squad members pass by you or through a window.
The entire game wouldnt be a huge story driven thing but that's normal for VR right? pretty sure they are more about the experience, the environment and the combat than anything else.
If i'm being honest I'd love it on console cause I dont wanna setup VR for pc but since Xbox hasnt got a VR (get on that please microsoft) i'd have to go get PSVR.
