Easy. I've seen many games with wall running. Warframe, prince of persia, pop 2008 to name a few. Just like many covered based 3rd person shooters. Examples, gears of war series, Uncharted series, rainbow six vegas series, army of two series, and im sure there is more. When they take cover they look different. Again. Call of duty has long ran out of ideas. Next year they will add teleporters like in halo. The year after they will add chainsaws from gears of war. The year after that, they will add elements to the guns from borderlands. Heck, they may even add in a turn based combat system from final fantasy and call it new. 😂