I'm not sure gaming engines can currently support multiple gaming formats as you propose. Tale for example the new unreal engine, great for open world - but if it's something a bit more specialist like anti gravity combat racing - unreal engine wouldn't be the best choice platform for the build.
As for virtual reality in gaming - it's becoming a thing. It's gonna be BIG. How about making a game where a budding young gamer who dreams of being a physician when he or she comes of age, can in virtual reality perform simple operations as part of a busy but underfunded hospital. The idea being, the gamer who has an interest in medical science, can perform a multitude of simulated reality operations and procedures within the virtual reality game.
Or
How about a virtual reality experience a city where Muslims have shops, schools, universities, museums, etc and you can walk around and use your credits to take lessons in things like archery, horse riding, visit the museums and libraries and speak to librarians and other interested Muslims about those topics etc? Bit like a forum, except, more interactive - virtual reality type. Not sure how we'd get around the whole avatar thing though.
I'm no expert, i'm just throwing ideas out here. Computer Gaming is a comtroversial issue within Islam. I think there is room for creative, educational experiences in gaming that do not fall into the haraam category per se.
Making that a reality, is up to guys like you, in sha Allah.
Scimi