A wizard duel game. 1v1. The gimmick is that you have to do the somatic (arm waving) component for your spells to fire. Could work with VR controllers or even a Kinect. The longer your arm travels, the stronger the spell becomes. You, as a wizard, can "create" a list of somatic components and attribute them to an effect, like "fire" or "darkness" or "lightning". By mixing and matching your waving, you could cast a variety of spells with different effects, like a lightning bolt that sets the enemy on fire and engulfs them in darkness. To avoid being hit, you could either finish a counterspell faster, hit the enemy with an appropriately strong spell (at least 1 somatic component less than his current casting) or set up shields that will absorb a number of damage before dissipating.
To make the game fancy, you'd be able to customize your wizard and your wizard tower, both of which would be the centerpieces of the duel. Everything you'd unlock through gameplay, no battlepass bullshit, no microtransactions, no bullshit grind to make it last longer than it should.
Magica on the PC had a really great intuitive spell system that was a "minute to learn, lifetime to master" sort of thing. I also played it with a controller, and found it lacking. But something like that PvP would be fun without waving your arms for 15 minutes at a time.
Damn that would be so cool! It's an excellent idea. And it doesn't seem too farfetched (I have no idea tho), but I can see it as one of the next big things. You are on to something man.
Also, username checks out.